Digital camera with printing assembly

ABSTRACT

A digital camera includes an image capture assembly, roll of print media and microelectromechanical stationary printhead. Upon capturing an image a central processing integrated circuit operates the printhead and associated transport assembly to print the captured image. A guillotine is provided to automatically severe each print. The guillotine operates a counter in order that an operator of the digital camera is able to keep track of how much print media remains on the roll.

This is a Continuation application of U.S. Ser. No. 10/729,151 filed onDec. 8, 2003 now U.S. Pat. No. 7,551,201 which is a continuation of Ser.No. 09/112,774 filed on Jul. 10, 1998 now abandoned all of which areherein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates substantially to the concept of adisposable camera having instant printing capabilities and inparticular, discloses an image capture and processing device for adigital camera system.

BACKGROUND OF THE INVENTION

Recently, the concept of a “single use” disposable camera has become anincreasingly popular consumer item. Disposable camera systems presentlyon the market normally include an internal film roll and a simplifiedgearing mechanism for traversing the film roll across an imaging systemincluding a shutter and lensing system. The user, after utilising asingle film roll returns the camera system to a film development centrefor processing. The film roll is taken out of the camera system andprocessed and the prints returned to the user. The camera system is thenable to be re-manufactured through the insertion of a new film roll intothe camera system, the replacement of any worn or wearable parts and there-packaging of the camera system in accordance with requirements. Inthis way, the concept of a single use “disposable” camera is provided tothe consumer.

Recently, a camera system has been proposed by the present applicantwhich provides for a handheld camera device having an internal printhead, image sensor and processing means such that images sense by theimage sensing means, are processed by the processing means and adaptedto be instantly printed out by the printing means on demand. Theproposed camera system further discloses a system of internal “printrolls” carrying print media such as film on to which images are to beprinted in addition to ink to supplying the printing means for theprinting process. The print roll is further disclosed to be detachableand replaceable within the camera system.

Unfortunately, such a system is likely to only be constructed at asubstantial cost and it would be desirable to provide for a moreinexpensive form of instant camera system which maintains a substantialnumber of the quality aspects of the aforementioned arrangement.

It would be further advantageous to provide for the effectiveinterconnection of the sub components of a camera system.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the invention, there is provided animage capture and processing device which comprises

an image sensor integrated circuit;

a plurality of analogue-to-digital converters (ADC's) that are connectedto the image sensor integrated circuit to convert analogue signalsgenerated by the image sensor integrated circuit into digital signals;

image processing circuitry that is connected to the ADC's to carry outimage processing operations on the digital signals and

a print head interface that is connected to the image processingcircuitry to receive data from the image processing circuitry and toformat that data correctly for a printhead.

A memory device may be interposed between the image sensor integratedcircuit and the image processing circuitry to store data relating to animage sensed by the image sensor integrated circuit.

The image sensor integrated circuit may define a CMOS active pixelsensor array. The image sensor integrated circuit may incorporate aplurality of analog signal processors that are configured to carry outenhancement processes on analog signals generated by the active pixelsensor array.

The image processing circuitry may include color interpolation circuitryto interpolate pixel data. The image processing circuitry may includeconvolver circuitry that is configured to apply a convolution process tothe image data.

The print head interface may be configured to format the data correctlyfor a pagewidth printhead.

The device may be a single integrated circuit.

The invention extends to a camera system that includes an image captureand processing device as described above.

In accordance with a second aspect of the present invention, there isprovided in a camera system comprising: an image sensor device forsensing an image; a processing means for processing the sensed image; aprint media supply means for the supply of print media to a print head;a print head for printing the sensed image on the print media storedinternally to the camera system; a portable power supply interconnectedto the print head, the sensor and the processing means; and a guillotinemechanism located between the print media supply means and the printhead and adapted to cut the print media into sheets of a predeterminedsize.

Further, preferably, the guillotine mechanism is detachable from thecamera system. The guillotine mechanism can be attached to the printmedia supply means and is detachable from the camera system with theprint media supply means. The guillotine mechanism can be mounted on aplaten unit below the print head.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of thepresent invention, preferred forms of the invention will now bedescribed, by way of example only, with reference to the accompanyingdrawings in which:

FIG. 1 illustrates a front perspective view of the assembled camera ofthe preferred embodiment;

FIG. 2 illustrates a rear perspective view, partly exploded, of thepreferred embodiment;

FIG. 3 is a perspective view of the chassis of the preferred embodiment;

FIG. 4 is a perspective view of the chassis illustrating mounting ofelectric motors;

FIG. 5 is an exploded perspective of the ink supply mechanism of thepreferred embodiment;

FIG. 6 is rear perspective of the assembled form of the ink supplymechanism of the preferred embodiment;

FIG. 7 is a front perspective view of the assembled form of the inksupply mechanism of the preferred embodiment;

FIG. 8 is an exploded perspective view of the platen unit of thepreferred embodiment;

FIG. 9 is a perspective view of the assembled form of the platen unit;

FIG. 10 is also a perspective view of the assembled form of the platenunit;

FIG. 11 is an exploded perspective view of the printhead recappingmechanism of the preferred embodiment;

FIG. 12 is a close up exploded perspective of the recapping mechanism ofthe preferred embodiment;

FIG. 13 is an exploded perspective of the ink supply cartridge of thepreferred embodiment;

FIG. 14 is a close up perspective, view partly in section, of theinternal portions of the ink supply cartridge in an assembled form;

FIG. 15 is a schematic block diagram of one form of integrated circuitlayer of the image capture and processing integrated circuit of thepreferred embodiment;

FIG. 16 is an exploded view perspective illustrating the assemblyprocess of the preferred embodiment;

FIG. 17 illustrates a front exploded perspective view of the assemblyprocess of the preferred embodiment;

FIG. 18 illustrates a perspective view of the assembly process of thepreferred embodiment;

FIG. 19 illustrates a perspective view of the assembly process of thepreferred embodiment;

FIG. 20 is a perspective view illustrating the insertion of the platenunit in the preferred embodiment;

FIG. 21 illustrates the interconnection of the electrical components ofthe preferred embodiment;

FIG. 22 illustrates the process of assembling the preferred embodiment;and

FIG. 23 is a perspective view further illustrating the assembly processof the preferred embodiment.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

Turning initially simultaneously to FIG. 1 and FIG. 2 there areillustrated perspective views of an assembled camera constructed inaccordance with the preferred embodiment with FIG. 1 showing a frontperspective view and FIG. 2 showing a rear perspective view. The camera1 includes a paper or plastic film jacket 2 which can include simplifiedinstructions 3 for the operation of the camera system 1. The camerasystem 1 includes a first “take” button 4 which is depressed to capturean image. The captured image is output via output slot 6. A further copyof the image can be obtained through depressing a second “printer copy”button 7 whilst an LED light 5 is illuminated. The camera system alsoprovides the usual view finder 8 in addition to a CCD imagecapture/lensing system 9.

The camera system 1 provides for a standard number of output printsafter which the camera system 1 ceases to function. A prints leftindicator slot 10 is provided to indicate the number of remainingprints. A refund scheme at the point of purchase is assumed to beoperational for the return of used camera systems for recycling.

Turning now to FIG. 3, the assembly of the camera system is based aroundan internal chassis 12 which can be a plastic injection molded part. Apair of paper pinch rollers 28, 29 utilized for decurling are snapfitted into corresponding frame holes eg. 26, 27.

As shown in FIG. 4, the chassis 12 includes a series of mutually opposedprongs eg. 13, 14 into which is snapped fitted a series of electricmotors 16, 17. The electric motors 16, 17 can be entirely standard withthe motor 16 being of a stepper motor type. The motor 16, 17 includecogs 19, 20 for driving a series of gear wheels. A first set of gearwheels is provided for controlling a paper cutter mechanism and a secondset is provided for controlling print roll movement.

Turning next to FIGS. 5 to 7, there is illustrated an ink supplymechanism 40 utilized in the camera system. FIG. 5 illustrates a backexploded perspective view, FIG. 6 illustrates a back assembled view andFIG. 7 illustrates a front assembled view. The ink supply mechanism 40is based around an ink supply cartridge 42 which contains printer inkand a print head mechanism for printing out pictures on demand. The inksupply cartridge 42 includes a side aluminium strip 43 which is providedas a shear strip to assist in cutting images from a paper roll.

A dial mechanism 44 is provided for indicating the number of “printsleft”. The dial mechanism 44 is snap fitted through a correspondingmating portion 46 so as to be freely rotatable.

As shown in FIG. 6, the mechanism 40 includes a flexible PCB strip 47which interconnects with the print head and provides for control of theprint head. The interconnection between the Flex PCB strip and an imagesensor and print head integrated circuit can be via Tape AutomatedBonding (TAB) Strips 51, 58. A moulded aspherical lens and aperture shim50 (FIG. 5) is also provided for imaging an image onto the surface ofthe image sensor integrated circuit normally located within cavity 53and a light box module or hood 52 is provided for snap fitting over thecavity 53 so as to provide for proper light control. A series ofdecoupling capacitors eg. 34 can also be provided. Further a plug 45(FIG. 7) is provided for re-plugging ink holes after refilling. A seriesof guide prongs eg. 55-57 are further provided for guiding the flexiblePCB strip 47.

The ink supply mechanism 40 interacts with a platen unit 60 which guidesprint media under a printhead located in the ink supply mechanism. FIG.8 shows an exploded view of the platen unit 60, while FIGS. 9 and 10show assembled views of the platen unit. The platen unit 60 includes afirst pinch roller 61 which is snap fitted to one side of a platen base62. Attached to a second side of the platen base 62 is a cuttingmechanism 63 which traverses the platen unit 60 by means of a rod 64having a screw thread which is rotated by means of cogged wheel 65 whichis also fitted to the platen base 62. The screw threaded rod 64 mounts ablock 67 which includes a cutting wheel 68 fastened via a fastener 69.Also mounted to the block 67 is a counter actuator which includes a pawl71 The pawl 71 acts to rotate the dial mechanism 44 of FIG. 6 upon thereturn traversal of the cutting wheel. As shown previously in FIG. 6,the dial mechanism 44 includes a cogged surface which interacts withpawl 71, thereby maintaining a count of the number of photographs bymeans of numbers embossed on the surface of dial mechanism 44. Thecutting mechanism 63 is inserted into the platen base 62 by means of asnap fit via clips 74.

The platen unit 60 includes an internal recapping mechanism 80 forrecapping the print head when not in use. The recapping mechanism 80includes a sponge portion 81 and is operated via a solenoid coil so asto provide for recapping of the print head. In the preferred embodiment,there is provided an inexpensive form of printhead recapping mechanismprovided for incorporation into a handheld camera system so as toprovide for printhead recapping of an inkjet printhead.

FIG. 11 illustrates an exploded view of the recapping mechanism whilstFIG. 12 illustrates a close up of the end portion thereof The re-cappingmechanism 80 is structured around a solenoid including a 16 turn coil 75which can comprise insulated wire. The coil 75 is turned around a firststationery solenoid arm 76 which is mounted on a bottom surface of theplaten base 62 (FIG. 8) and includes a post portion 77 to magnifyeffectiveness of operation. The arm 76 can comprise a ferrous material.

A second moveable arm 78 of the solenoid actuator is also provided. Thearm 78 is moveable and is also made of ferrous material. Mounted on thearm is a sponge portion surrounded by an elastomer strip 79. Theelastomer strip 79 is of a generally arcuate cross-section and act as aleaf spring against the surface of the printhead ink supply cartridge 42(FIG. 5) so as to provide for a seal against the surface of theprinthead ink supply cartridge 42. In the quiescent position anelastomer spring unit 87, 88 acts to resiliently deform the elastomerseal 79 against the surface of the ink supply unit 42.

When it is desired to operate the printhead unit, upon the insertion ofpaper, the solenoid coil 75 is activated so as to cause the arm 78 tomove down to be adjacent to the end plate 76. The arm 78 is held againstend plate 76 while the printhead is printing by means of a small “keepercurrent” in coil 75. Simulation results indicate that the keeper currentcan be significantly less than the actuation current. Subsequently,after photo printing, the paper is guillotined by the cutting mechanism63 of FIG. 8 acting against Aluminium Strip 43, and rewound so as toclear the area of the re-capping mechanism 80. Subsequently, the currentis turned off and springs 87, 88 return the arm 78 so that the elastomerseal is again resting against the printhead ink supply cartridge.

It can be seen that the preferred embodiment provides for a simple andinexpensive means of re-capping a printhead through the utilisation of asolenoid type device having a long rectangular form. Further, thepreferred embodiment utilises minimal power in that currents are onlyrequired whilst the device is operational and additionally, only a lowkeeper current is required whilst the printhead is printing.

Turning next to FIGS. 13 and 14, FIG. 13 illustrates an explodedperspective of the ink supply cartridge 42 whilst FIG. 14 illustrates aclose up sectional view of a bottom of the ink supply cartridge with theprinthead unit in place. The ink supply cartridge 42 is based around apagewidth printhead 102 which comprises a long slither of silicon havinga series of holes etched on the back surface for the supply of ink to afront surface of the silicon wafer for subsequent ejection via a microelectro mechanical system. The form of ejection can be many differentforms such as those set out in the tables below.

Of course, many other inkjet technologies, as referred to the attachedtables below, can also be utilised when constructing a printhead unit102. The fundamental requirement of the ink supply cartridge 42 is thesupply of ink to a series of colour channels etched through the backsurface of the printhead 102. In the description of the preferredembodiment, it is assumed that a three colour printing process is to beutilised so as to provide full colour picture output. Hence, the printsupply unit includes three ink supply reservoirs being a cyan reservoir104, a magenta reservoir 105 and a yellow reservoir 106. Each of thesereservoirs is required to store ink and includes a corresponding spongetype material 107-109 which assists in stabilising ink within thecorresponding ink channel and inhibiting the ink from sloshing back andforth when the printhead is utilised in a handheld camera system. Thereservoirs 104, 105, 106 are formed through the mating of first exteriorplastic piece 110 and a second base piece 111.

At a first end 118 of the base piece 111 a series of air inlet 113-115are provided. Each air inlet leads to a corresponding winding channelwhich is hydrophobically treated so as to act as an ink repellent andtherefore repel any ink that may flow along the air inlet channel. Theair inlet channel further takes a convoluted path assisting in resistingany ink flow out of the chambers 104-106. An adhesive tape portion 117is provided for sealing the channels within end portion 118.

At the top end, there is included a series of refill holes (not shown)for refilling corresponding ink supply chambers 104, 105, 106. A plug121 is provided for sealing the refill holes.

Turning now to FIG. 14, there is illustrated a close up perspectiveview, partly in section through the ink supply cartridge 42 of FIG. 13when formed as a unit. The ink supply cartridge includes the threecolour ink reservoirs 104, 105, 106 which supply ink to differentportions of the back surface of printhead 102 which includes a series ofapertures 128 defined therein for carriage of the ink to the frontsurface.

The ink supply cartridge 42 includes two guide walls 124, 125 whichseparate the various ink chambers and are tapered into an end portionabutting the surface of the printhead 102. The guide walls 124, 125 arefurther mechanically supported by block portions eg. 126 which areplaced at regular intervals along the length of the ink supply unit. Theblock portions 126 leave space at portions close to the back ofprinthead 102 for the flow of ink around the back surface thereof.

The ink supply unit is preferably formed from a multi-part plasticinjection mould and the mould pieces eg. 110, 111 (FIG. 13) snaptogether around the sponge pieces 107, 109. Subsequently, a syringe typedevice can be inserted in the ink refill holes and the ink reservoirsfilled with ink with the air flowing out of the air outlets 113-115.Subsequently, the adhesive tape portion 117 and plug 121 are attachedand the printhead tested for operation capabilities. Subsequently, theink supply cartridge 42 can be readily removed for refilling by means ofremoving the ink supply cartridge, performing a washing cycle, and thenutilising the holes for the insertion of a refill syringe filled withink for refilling the ink chamber before returning the ink supplycartridge 42 to a camera.

Turning now to FIG. 15, there is shown an example layout of the ImageCapture and Processing integrated circuit (ICP) 48.

The Image Capture and Processing integrated circuit 48 provides most ofthe electronic functionality of the camera with the exception of theprint head integrated circuit. The integrated circuit 48 is a highlyintegrated system. It combines CMOS image sensing, analog to digitalconversion, digital image processing, DRAM storage, ROM, andmiscellaneous control functions in a single integrated circuit.

The integrated circuit is estimated to be around 32 mm² using a leadingedge 0.18 micron CMOS/DRAM/APS process. The integrated circuit size andcost can scale somewhat with Moore's law, but is dominated by a CMOSactive pixel sensor array 201, so scaling is limited as the sensorpixels approach the diffraction limit.

The ICP 48 includes CMOS logic, a CMOS image sensor, DRAM, and analogcircuitry. A very small amount of flash memory or other non-volatilememory is also preferably included for protection against reverseengineering.

Alternatively, the ICP can readily be divided into two integratedcircuits: one for the CMOS imaging array, and the other for theremaining circuitry. The cost of this two integrated circuit solutionshould not be significantly different than the single integrated circuitICP, as the extra cost of packaging and bond-pad area is somewhatcancelled by the reduced total wafer area requiring the color filterfabrication steps.

The ICP preferably contains the following functions:

Function 1.5 megapixel image sensor Analog Signal Processors Imagesensor column decoders Image sensor row decoders Analogue to DigitalConversion (ADC) Column ADC's Auto exposure 12 Mbits of DRAM DRAMAddress Generator Color interpolator Convolver Color ALU Halftone matrixROM Digital halftoning Print head interface 8 bit CPU core Program ROMFlash memory Scratchpad SRAM Parallel interface (8 bit) Motor drivetransistors (5) Clock PLL JTAG test interface Function Test circuitsBusses Bond pads

The CPU, DRAM, Image sensor, ROM, Flash memory, Parallel interface, JTAGinterface and ADC can be vendor supplied cores. The ICP is intended torun on 1.5V to minimize power consumption and allow convenient operationfrom two AA type battery cells.

FIG. 15 illustrates a layout of the ICP 48. The ICP 48 is dominated bythe imaging array 201, which consumes around 80% of the integratedcircuit area. The imaging array is a CMOS 4 transistor active pixeldesign with a resolution of 1,500×1,000. The array can be divided intothe conventional configuration, with two green pixels, one red pixel,and one blue pixel in each pixel group. There are 750×500 pixel groupsin the imaging array.

The latest advances in the field of image sensing and CMOS image sensingin particular can be found in the October, 1997 issue of IEEETransactions on Electron Devices and, in particular, pages 1689 to 1968.Further, a specific implementation similar to that disclosed in thepresent application is disclosed in Wong et. al, “CMOS Active PixelImage Sensors Fabricated Using a 1.8V, 0.25 μm CMOS Technology”, IEDM1996, page 915

The imaging array uses a 4 transistor active pixel design of a standardconfiguration. To minimize integrated circuit area and therefore cost,the image sensor pixels should be as small as feasible with thetechnology available. With a four transistor cell, the typical pixelsize scales as 20 times the lithographic feature size. This allows aminimum pixel area of around 3.6 μm×3.6 μm. However, the photosite mustbe substantially above the diffraction limit of the lens. It is alsoadvantageous to have a square photosite, to maximize the margin over thediffraction limit in both horizontal and vertical directions. In thiscase, the photosite can be specified as 2.5 μm×2.5 μm. The photosite canbe a photogate, pinned photodiode, charge modulation device, or othersensor.

The four transistors are packed as an ‘L’ shape, rather than arectangular region, to allow both the pixel and the photosite to besquare. This reduces the transistor packing density slightly, increasingpixel size. However, the advantage in avoiding the diffraction limit isgreater than the small decrease in packing density.

The transistors also have a gate length which is longer than the minimumfor the process technology. These have been increased from a drawnlength of 0.18 micron to a drawn length of 0.36 micron. This is toimprove the transistor matching by making the variations in gate lengthrepresent a smaller proportion of the total gate length.

The extra gate length, and the ‘L’ shaped packing, mean that thetransistors use more area than the minimum for the technology. Normally,around 8 μm² would be required for rectangular packing. Preferably, 9.75μm² has been allowed for the transistors.

The total area for each pixel is 16 μm², resulting from a pixel size of4 μm×4 μm. With a resolution of 1,500×1,000, the area of the imagingarray 101 is 6,000 μm×4,000 μm, or 24 mm².

The presence of a color image sensor on the integrated circuit affectsthe process required in two major ways:

-   -   The CMOS fabrication process should be optimized to minimize        dark current

Color filters are required. These can be fabricated using dyedphotosensitive polyimides, resulting in an added process complexity ofthree spin coatings, three photolithographic steps, three developmentsteps, and three hardbakes.

There are 15,000 analog signal processors (ASPs) 205, one for each ofthe columns of the sensor. The ASPs amplify the signal, provide a darkcurrent reference, sample and hold the signal, and suppress the fixedpattern noise (FPN).

There are 375 analog to digital converters 206, one for each fourcolumns of the sensor array. These may be delta-sigma or successiveapproximation type ADC's. A row of low column ADC's are used to reducethe conversion speed required, and the amount of analog signaldegradation incurred before the signal is converted to digital. Thisalso eliminates the hot spot (affecting local dark current) and thesubstrate coupled noise that would occur if a single high speed ADC wasused. Each ADC also has two four bit DAC's which trim the offset andscale of the ADC to further reduce FPN variations between columns. TheseDAC's are controlled by data stored in flash memory during integratedcircuit testing.

The column select logic 204 is a 1:1500 decoder which enables theappropriate digital output of the ADCs onto the output bus. As each ADCis shared by four columns, the least significant two bits of the rowselect control 4 input analog multiplexors.

A row decoder 207 is a 1:1000 decoder which enables the appropriate rowof the active pixel sensor array. This selects which of the 1000 rows ofthe imaging array is connected to analog signal processors. As the rowsare always accessed in sequence, the row select logic can be implementedas a shift register.

An auto exposure system 208 adjusts the reference voltage of the ADC 205in response to the maximum intensity sensed during the previous frameperiod. Data from the green pixels is passed through a digital peakdetector. The peak value of the image frame period before capture (thereference frame) is provided to a digital to analogue converter(DAC),which generates the global reference voltage for the column ADCs. Thepeak detector is reset at the beginning of the reference frame. Theminimum and maximum values of the three RGB color components are alsocollected for color correction.

The second largest section of the integrated circuit is consumed by aDRAM 210 used to hold the image. To store the 1,500×1,000 image from thesensor without compression, 1.5 Mbytes of DRAM 210 are required. Thisequals 12 Mbits, or slightly less than 5% of a 256 Mbit DRAM. The DRAMtechnology assumed is of the 256 Mbit generation implemented using 0.18μm CMOS.

Using a standard 8F cell, the area taken by the memory array is 3.11mm². When row decoders, column sensors, redundancy, and other factorsare taken into account, the DRAM requires around 4 mm².

This DRAM 210 can be mostly eliminated if analog storage of the imagesignal can be accurately maintained in the CMOS imaging array for thetwo seconds required to print the photo. However, digital storage of theimage is preferable as it is maintained without degradation, isinsensitive to noise, and allows copies of the photo to be printedconsiderably later.

A DRAM address generator 211 provides the write and read addresses tothe DRAM 210. Under normal operation, the write address is determined bythe order of the data read from the CMOS image sensor 201. This willtypically be a simple raster format. However, the data can be read fromthe sensor 201 in any order, if matching write addresses to the DRAM aregenerated. The read order from the DRAM 210 will normally simply matchthe requirements of a color interpolator and the print head. As thecyan, magenta, and yellow rows of the print head are necessarily offsetby a few pixels to allow space for nozzle actuators, the colors are notread from the DRAM simultaneously. However, there is plenty of time toread all of the data from the DRAM many times during the printingprocess. This capability is used to eliminate the need for FIFOs in theprint head interface, thereby saving integrated circuit area. All threeRGB image components can be read from the DRAM each time color data isrequired. This allows a color space converter to provide a moresophisticated conversion than a simple linear RGB to CMY conversion.

Also, to allow two dimensional filtering of the image data withoutrequiring line buffers, data is re-read from the DRAM array.

The address generator may also implement image effects in certain modelsof camera. For example, passport photos are generated by a manipulationof the read addresses to the DRAM. Also, image framing effects (wherethe central image is reduced), image warps, and kaleidoscopic effectscan all be generated by manipulating the read addresses of the DRAM.

While the address generator 211 may be implemented with substantialcomplexity if effects are built into the standard integrated circuit,the integrated circuit area required for the address generator is small,as it consists only of address counters and a moderate amount of randomlogic.

A color interpolator 214 converts the interleaved pattern of red,2×green, and blue pixels into RGB pixels. It consists of three 8 bitadders and associated registers. The divisions are by either 2 (forgreen) or 4 (for red and blue) so they can be implemented as fixedshifts in the output connections of the adders.

A convolver 215 is provided as a sharpening filter which applies a smallconvolution kernel (5×5) to the red, green, and blue planes of theimage. The convolution kernel for the green plane is different from thatof the red and blue planes, as green has twice as many samples. Thesharpening filter has five functions:

-   -   To improve the color interpolation from the linear interpolation        provided by the color interpolator, to a close approximation of        a sinc interpolation.    -   To compensate for the image ‘softening’ which occurs during        digitization.    -   To adjust the image sharpness to match average consumer        preferences, which are typically for the image to be slightly        sharper than reality. As the single use camera is intended as a        consumer product, and not a professional photographic products,        the processing can match the most popular settings, rather than        the most accurate.    -   To suppress the sharpening of high frequency (individual pixel)        noise. The function is similar to the ‘unsharp mask’ process.    -   To antialias Image Warping.

These functions are all combined into a single convolution matrix. Asthe pixel rate is low (less than 1 Mpixel per second) the total numberof multiplies required for the three color channels is 56 millionmultiplies per second. This can be provided by a single multiplier.Fifty bytes of coefficient ROM are also required.

A color ALU 113 combines the functions of color compensation and colorspace conversion into the one matrix multiplication, which is applied toevery pixel of the frame. As with sharpening, the color correctionshould match the most popular settings, rather than the most accurate.

A color compensation circuit of the color ALU provides compensation forthe lighting of the photo. The vast majority of photographs aresubstantially improved by a simple color compensation, whichindependently normalizes the contrast and brightness of the three colorcomponents.

A color look-up table (CLUT) 212 is provided for each color component.These are three separate 256×8 SRAMs, requiring a total of 6,144 bits.The CLUTs are used as part of the color correction process. They arealso used for color special effects, such as stochastically selected“wild color” effects.

A color space conversion system of the color ALU converts from the RGBcolor space of the image sensor to the CMY color space of the printer.The simplest conversion is a 1's complement of the RGB data. However,this simple conversion assumes perfect linearity of both color spaces,and perfect dye spectra for both the color filters of the image sensor,and the ink dyes. At the other extreme is a tri-linear interpolation ofa sampled three dimensional arbitrary transform table. This caneffectively match any non-linearity or differences in either colorspace. Such a system is usually necessary to obtain good color spaceconversion when the print engine is a color electrophotographic

However, since the non-linearity of a halftoned ink jet output is verysmall, a simpler system can be used. A simple matrix multiply canprovide excellent results. This requires nine multiplies and sixadditions per contone pixel. However, since the contone pixel rate islow (less than 1 Mpixel/sec) these operations can share a singlemultiplier and adder. The multiplier and adder are used in a color ALUwhich is shared with the color compensation function.

Digital halftoning can be performed as a dispersed dot ordered ditherusing a stochastic optimized dither cell. A halftone matrix ROM 216 isprovided for storing dither cell coefficients. A dither cell size of32×32 is adequate to ensure that the cell repeat cycle is not visible.The three colors—cyan, magenta, and yellow—are all dithered using thesame cell, to ensure maximum co-positioning of the ink dots. Thisminimizes ‘muddying’ of the mid-tones which results from bleed of dyesfrom one dot to adjacent dots while still wet. The total ROM sizerequired is 1 KByte, as the one ROM is shared by the halftoning unitsfor each of the three colors.

The digital halftoning used is dispersed dot ordered dither withstochastic optimized dither matrix. While dithering does not produce animage quite as ‘sharp’ as error diffusion, it does produce a moreaccurate image with fewer artifacts. The image sharpening produced byerror diffusion is artificial, and less controllable and accurate than‘unsharp mask’ filtering performed in the contone domain. The high printresolution (1,600 dpi×1,600 dpi) results in excellent quality when usinga well formed stochastic dither matrix.

Digital halftoning is performed by a digital halftoning unit 217 using asimple comparison between the contone information from the DRAM 210 andthe contents of the dither matrix 216. During the halftone process, theresolution of the image is changed from the 250 dpi of the capturedcontone image to the 1,600 dpi of the printed image. Each contone pixelis converted to an average of 40.96 halftone dots.

The ICP incorporates a 16 bit microcontroller CPU core 219 to run themiscellaneous camera functions, such as reading the buttons, controllingthe motor and solenoids, setting up the hardware, and authenticating therefill station. The processing power required by the CPU is very modest,and a wide variety of processor cores can be used. As the entire CPUprogram is run from a small ROM 220, program compatibility betweencamera versions is not important, as no external programs are run. A 2Mbit (256 Kbyte) program and data ROM 220 is included on integratedcircuit. Most of this ROM space is allocated to data for outlinegraphics and fonts for specialty cameras. The program requirements areminor. The single most complex task is the encrypted authentication ofthe refill station. The ROM requires a single transistor per bit.

A Flash memory 221 may be used to store a 128 bit authentication code.This provides higher security than storage of the authentication code inROM, as reverse engineering can be made essentially impossible. TheFlash memory is completely covered by third level metal, making the dataimpossible to extract using scanning probe microscopes or electronbeams. The authentication code is stored in the integrated circuit whenmanufactured. At least two other Flash bits are required for theauthentication process: a bit which locks out reprogramming of theauthentication code, and a bit which indicates that the camera has beenrefilled by an authenticated refill station. The flash memory can alsobe used to store FPN correction data for the imaging array.Additionally, a phase locked loop rescaling parameter is stored forscaling the clocking cycle to an appropriate correct time. The clockfrequency does not require crystal accuracy since no date functions areprovided. To eliminate the cost of a crystal, an on integrated circuitoscillator with a phase locked loop 224 is used. As the frequency of anon-integrated circuit oscillator is highly variable from integratedcircuit to integrated circuit, the frequency ratio of the oscillator tothe PLL is digitally trimmed during initial testing. The value is storedin Flash memory 221. This allows the clock PLL to control the ink-jetheater pulse width with sufficient accuracy.

A scratchpad SRAM is a small static RAM 222 with a 6T cell. Thescratchpad provided temporary memory for the 16 bit CPU. 1024 bytes isadequate.

A print head interface 223 formats the data correctly for the printhead. The print head interface also provides all of the timing signalsrequired by the print head. These timing signals may vary depending upontemperature, the number of dots printed simultaneously, the print mediumin the print roll, and the dye density of the ink in the print roll.

The following is a table of external connections to the print headinterface:

Connection Function Pins DataBits[0-7] Independent serial data to theeight segments 8 of the print head BitClock Main data clock for theprint head 1 ColorEnable[0-2] Independent enable signals for the CMY 3actuators, allowing different pulse times for each color.BankEnable[0-1] Allows either simultaneous or interleaved 2 actuation oftwo banks of nozzles. This allows two different print speed/powerconsumption tradeoffs NozzleSelect[0-4] Selects one of 32 banks ofnozzles for 5 simultaneous actuation ParallelXferClock Loads theparallel transfer register with the 1 data from the shift registersTotal 20

The print head utilized is composed of eight identical segments, each1.25 cm long. There is no connection between the segments on the printhead integrated circuit. Any connections required are made in theexternal TAB bonding film, which is double sided. The division intoeight identical segments is to simplify lithography using wafersteppers. The segment width of 1.25 cm fits easily into a stepper field.As the print head integrated circuit is long and narrow (10 cm×0.3 mm),the stepper field contains a single segment of 32 print head integratedcircuits. The stepper field is therefore 1.25 cm×1.6 cm. An average offour complete print heads are patterned in each wafer step.

A single BitClock output line connects to all 8 segments on the printhead. The 8 DataBits lines lead one to each segment, and are clockedinto the 8 segments on the print head simultaneously (on a BitClockpulse). For example, dot 0 is transferred to segment₀, dot 750 istransferred to segment₁, dot 1500 to segment₂ etc simultaneously.

The ParallelXferClock is connected to each of the 8 segments on theprint head, so that on a single pulse, all segments transfer their bitsat the same time.

The NozzleSelect, BankEnable and ColorEnable lines are connected to eachof the 8 segments, allowing the print head interface to independentlycontrol the duration of the cyan, magenta, and yellow nozzle energizingpulses. Registers in the Print Head Interface allow the accuratespecification of the pulse duration between 0 and 6 ms, with a typicalduration of 2 ms to 3 ms.

A parallel interface 125 connects the ICP to individual staticelectrical signals. The CPU is able to control each of these connectionsas memory mapped I/O via a low speed bus.

The following is a table of connections to the parallel interface:

Connection Direction Pins Paper transport stepper motor Output 4 Cappingsolenoid Output 1 Copy LED Output 1 Photo button Input 1 Copy buttonInput 1 Total 8

Seven high current drive transistors eg. 227 are required. Four are forthe four phases of the main stepper motor, two are for the guillotinemotor, and the remaining transistor is to drive the capping solenoid.These transistors are allocated 20,000 square microns (600,000 F) each.As the transistors are driving highly inductive loads, they must eitherbe turned off slowly, or be provided with a high level of back EMFprotection. If adequate back EMF protection cannot be provided using theintegrated circuit process chosen, then external discrete transistorsshould be used. The transistors are never driven at the same time as theimage sensor is used. This is to avoid voltage fluctuations and hotspots affecting the image quality. Further, the transistors are locatedas far away from the sensor as possible.

A standard JTAG (Joint Test Action Group) interface 228 is included inthe ICP for testing purposes and for interrogation by the refillstation. Due to the complexity of the integrated circuit, a variety oftesting techniques are required, including BIST (Built In Self Test) andfunctional block isolation. An overhead of 10% in integrated circuitarea is assumed for integrated circuit testing circuitry for the randomlogic portions. The overhead for the large arrays the image sensor andthe DRAM is smaller.

The JTAG interface is also used for authentication of the refillstation. This is included to ensure that the cameras are only refilledwith quality paper and ink at a properly constructed refill station,thus preventing inferior quality refills from occurring. The camera mustauthenticate the refill station, rather than vice versa. The secureprotocol is communicated to the refill station during the automated testprocedure. Contact is made to four gold plated spots on the ICP/printhead TAB by the refill station as the new ink is injected into the printhead.

FIG. 16 illustrates a rear view of the next step in the constructionprocess whilst FIG. 17 illustrates a front view.

Turning now to FIG. 16, the assembly of the camera system proceeds viafirst assembling the ink supply mechanism 40. The flex PCB isinterconnected with batteries 84 only one of which is shown, which areinserted in the middle portion of a print roll 85 which is wrappedaround a plastic former 86. An end cap 89 is provided at the other endof the print roll 85 so as to fasten the print roll and batteries firmlyto the ink supply mechanism.

The solenoid coil is interconnected (not shown) to interconnects 97, 98(FIG. 8) which include leaf spring ends for interconnection withelectrical contacts on the Flex PCB so as to provide for electricalcontrol of the solenoid.

Turning now to FIGS. 17-19 the next step in the construction process isthe insertion of the relevant gear trains into the side of the camerachassis. FIG. 17 illustrates a front view, FIG. 18 illustrates a rearview and FIG. 19 also illustrates a rear view. The first gear traincomprising gear wheels 22, 23 is utilised for driving the guillotineblade with the gear wheel 23 engaging the gear wheel 65 of FIG. 8. Thesecond gear train comprising gear wheels 24, 25 and 26 engage one end ofthe print roller 61 of FIG. 8. As best indicated in FIG. 18, the gearwheels mate with corresponding pins on the surface of the chassis withthe gear wheel 26 being snap fitted into corresponding mating hole 27.

Next, as illustrated in FIG. 20, the assembled platen unit 60 is theninserted between the print roll 85 and aluminium cutting blade 43.

Turning now to FIG. 21, by way of illumination, there is illustrated theelectrically interactive components of the camera system. As notedpreviously, the components are based around a Flex PCB board and includea TAB film 58 which interconnects the printhead 102 with the imagesensor and processing integrated circuit 48. Power is supplied by two AAtype batteries 83, 84 and a paper drive stepper motor 16 is provided inaddition to a rotary guillotine motor 17.

An optical element 31 is provided for snapping into a top portion of thechassis 12. The optical element 31 includes portions defining an opticalview finder 32, 33 which are slotted into mating portions 35, 36 in viewfinder channel 37. Also provided in the optical element 31 is a lensingsystem 38 for magnification of the prints left number in addition to anoptical pipe element 39 for piping light from the LED 5 for externaldisplay.

Turning next to FIG. 22, the assembled unit 90 is then inserted into afront outer case 91 which includes button 4 for activation of printouts.

Turning now to FIG. 23, next, the unit 90 is provided with a snap-onback cover 93 which includes a slot 6 and copy print button 7. A wrapperlabel containing instructions and advertising (not shown) is thenwrapped around the outer surface of the camera system and pinch clampedto the cover by means of clamp strip 96 which can comprise a flexibleplastic or rubber strip.

Subsequently, the preferred embodiment is ready for use as a one timeuse camera system that provides for instant output images on demand. Itwill be evident that the preferred embodiment further provides for arefillable camera system. A used camera can be collected and its outerplastic cases removed and recycled. A new paper roll and batteries canbe added and the ink cartridge refilled. A series of automatic testroutines can then be carried out to ensure that the printer is properlyoperational. Further, in order to ensure only authorised refills areconducted so as to enhance quality, routines in the on-integratedcircuit program ROM can be executed such that the camera authenticatesthe refilling station using a secure protocol. Upon authentication, thecamera can reset an internal paper count and an external case can befitted on the camera system with a new outer label. Subsequent packingand shipping can then take place.

It will be further readily evident to those skilled in the art that theprogram ROM can be modified so as to allow for a variety of digitalprocessing routines. In addition to the digitally enhanced photographsoptimised for mainstream consumer preferences, various other models canreadily be provided through mere re-programming of the program ROM. Forexample, a sepia classic old fashion style output can be providedthrough a remapping of the colour mapping function. A furtheralternative is to provide for black and white outputs again through asuitable colour remapping algorithm. Minimum colour can also be providedto add a touch of colour to black and white prints to produce the effectthat was traditionally used to colourize black and white photos.Further, passport photo output can be provided through suitable addressremappings within the address generators. Further, edge filters can beutilised as is known in the field of image processing to producesketched art styles. Further, classic wedding borders and designs can beplaced around an output image in addition to the provision of relevantclip arts. For example, a wedding style camera might be provided.Further, a panoramic mode can be provided so as to output the well knownpanoramic format of images. Further, a postcard style output can beprovided through the printing of postcards including postage on the backof a print roll surface. Further, cliparts can be provided for specialevents such as Halloween, Christmas etc. Further, kaleidoscopic effectscan be provided through address remappings and wild colour effects canbe provided through remapping of the colour lookup table. Many otherforms of special event cameras can be provided for example, camerasdedicated to the Olympics, movie tie-ins, advertising and other specialevents.

The operational mode of the camera can be programmed so that upon thedepressing of the take photo a first image is sampled by the sensorarray to determine irrelevant parameters. Next a second image is againcaptured which is utilised for the output The captured image is thenmanipulated in accordance with any special requirements before beinginitially output on the paper roll. The LED light is then activated fora predetermined time during which the DRAM is refreshed so as to retainthe image. If the print copy button is depressed during thispredetermined time interval, a further copy of the photo is output Afterthe predetermined time interval where no use of the camera has occurred,the onboard CPU shuts down all power to the camera system until suchtime as the take button is again activated. In this way, substantialpower savings can be realized.

Ink Jet Technologies

The embodiments of the invention use an ink jet printer type device. Ofcourse many different devices could be used. However presently popularink jet printing technologies are unlikely to be suitable.

The most significant problem with thermal inkjet is power consumption.This is approximately 100 times that required for high speed, and stemsfrom the energy-inefficient means of drop ejection. This involves therapid boiling of water to produce a vapor bubble which expels the ink.Water has a very high heat capacity, and must be superheated in thermalinkjet applications. This leads to an efficiency of around 0.02%, fromelectricity input to drop momentum (and increased surface area) out.

The most significant problem with piezoelectric inkjet is size and cost.Piezoelectric crystals have a very small deflection at reasonable drivevoltages, and therefore require a large area for each nozzle. Also, eachpiezoelectric actuator must be connected to its drive circuit on aseparate substrate. This is not a significant problem at the currentlimit of around 300 nozzles per print head, but is a major impediment tothe fabrication of pagewide print heads with 19,200 nozzles.

Ideally, the inkjet technologies used meet the stringent requirements ofin-camera digital color printing and other high quality, high speed, lowcost printing applications. To meet the requirements of digitalphotography, new inkjet technologies have been created. The targetfeatures include:

low power (less than 10 Watts)

high resolution capability (1,600 dpi or more)

photographic quality output

low manufacturing cost

small size (pagewidth times minimum cross section)

high speed (<2 seconds per page).

All of these features can be met or exceeded by the inkjet systemsdescribed below with differing levels of difficulty. 45 different inkjettechnologies have been developed by the Assignee to give a wide range ofchoices for high volume manufacture. These technologies form part ofseparate applications assigned to the present Assignee as set out in thetable below.

The inkjet designs shown here are suitable for a wide range of digitalprinting systems, from battery powered one-time use digital cameras,through to desktop and network printers, and through to commercialprinting systems

For ease of manufacture using standard process equipment, the print headis designed to be a monolithic 0.5 micron CMOS integrated circuit withMEMS post processing. For color photographic applications, the printhead is 100 mm long, with a width which depends upon the inkjet type.The smallest print head designed is IJ38, which is 0.35 mm wide, givinga integrated circuit area of 35 square mm. The print heads each contain19,200 nozzles plus data and control circuitry.

Ink is supplied to the back of the print head by injection moldedplastic ink channels. The molding requires 50 micron features, which canbe created using a lithographically micromachined insert in a standardinjection molding tool. Ink flows through holes etched through the waferto the nozzle chambers fabricated on the front surface of the wafer. Theprint head is connected to the camera circuitry by tape automatedbonding.

Cross-Referenced Applications

The following table is a guide to cross-referenced patent applicationsfiled concurrently herewith and discussed hereinafter with the referencebeing utilized in subsequent tables when referring to a particular case:

Reference Title IJ01 Radiant Plunger Ink Jet Printer IJ02 ElectrostaticInk Jet Printer IJ03 Planar Thermoelastic Bend Actuator Ink Jet IJ04Stacked Electrostatic Ink Jet Printer IJ05 Reverse Spring Lever Ink JetPrinter IJ06 Paddle Type Ink Jet Printer IJ07 Permanent MagnetElectromagnetic Ink Jet Printer IJ08 Planar Swing Grill ElectromagneticInk Jet Printer IJ09 Pump Action Refill Ink Jet Printer IJ10 PulsedMagnetic Field Ink Jet Printer IJ11 Two Plate Reverse FiringElectromagnetic Ink Jet Printer IJ12 Linear Stepper Actuator Ink JetPrinter IJ13 Gear Driven Shutter Ink Jet Printer IJ14 Tapered MagneticPole Electromagnetic Ink Jet Printer IJ15 Linear Spring ElectromagneticGrill Ink Jet Printer IJ16 Lorenz Diaphragm Electromagnetic Ink JetPrinter IJ17 PTFE Surface Shooting Shuttered Oscillating Pressure InkJet Printer IJ18 Buckle Grip Oscillating Pressure Ink Jet Printer IJ19Shutter Based Ink Jet Printer IJ20 Curling Calyx Thermoelastic Ink JetPrinter IJ21 Thermal Actuated Ink Jet Printer IJ22 Iris Motion Ink JetPrinter IJ23 Direct Firing Thermal Bend Actuator Ink Jet Printer IJ24Conductive PTFE Ben Activator Vented Ink Jet Printer IJ25Magnetostrictive Ink Jet Printer IJ26 Shape Memory Alloy Ink Jet PrinterIJ27 Buckle Plate Ink Jet Printer IJ28 Thermal Elastic Rotary ImpellerInk Jet Printer IJ29 Thermoelastic Bend Actuator Ink Jet Printer IJ30Thermoelastic Bend Actuator Using PTFE and Corrugated Copper Ink JetPrinter IJ31 Bend Actuator Direct Ink Supply Ink Jet Printer IJ32 A HighYoung's Modulus Thermoelastic Ink Jet Printer IJ33 Thermally actuatedslotted chamber wall ink jet printer IJ34 Ink Jet Printer having athermal actuator comprising an ex- ternal coiled spring IJ35 TroughContainer Ink Jet Printer IJ36 Dual Chamber Single Vertical Actuator InkJet IJ37 Dual Nozzle Single Horizontal Fulcrum Actuator Ink Jet IJ38Dual Nozzle Single Horizontal Actuator Ink Jet IJ39 A single bendactuator cupped paddle ink jet printing device IJ40 A thermally actuatedink jet printer having a series of ther- mal actuator units IJ41 Athermally actuated ink jet printer including a tapered heater elementIJ42 Radial Back-Curling Thermoelastic Ink Jet IJ43 Inverted RadialBack-Curling Thermoelastic Ink Jet IJ44 Surface bend actuator vented inksupply ink jet printer IJ45 Coil Acutuated Magnetic Plate Ink JetPrinterTables of Drop-On-Demand Inkjets

Eleven important characteristics of the fundamental operation ofindividual inkjet nozzles have been identified. These characteristicsare largely orthogonal, and so can be elucidated as an elevendimensional matrix. Most of the eleven axes of this matrix includeentries developed by the present assignee.

The following tables form the axes of an eleven dimensional table ofinkjet types.

-   Actuator mechanism (18 types)-   Basic operation mode (7 types)-   Auxiliary mechanism (8 types)-   Actuator amplification or modification method (17 types)-   Actuator motion (19 types)-   Nozzle refill method (4 types)-   Method of restricting back-flow through inlet (10 types)-   Nozzle clearing method (9 types)-   Nozzle plate construction (9 types)-   Drop ejection direction (5 types)-   Ink type (7 types)

The complete eleven dimensional table represented by these axes contains36.9 billion possible configurations of inkjet nozzle. While not all ofthe possible combinations result in a viable inkjet technology, manymillion configurations are viable. It is clearly impractical toelucidate all of the possible configurations. Instead, certain inkjettypes have been investigated in detail. These are designated IJ01 toIJ45 above.

Other inkjet configurations can readily be derived from these 45examples by substituting alternative configurations along one or more ofthe 11 axes. Most of the IJ01 to U45 examples can be made into inkjetprint heads with characteristics superior to any currently availableinkjet technology.

Where there are prior art examples known to the inventor, one or more ofthese examples are listed in the examples column of the tables below.The IJ01 to IJ45 series are also listed in the examples column. In somecases, a printer may be listed more than once in a table, where itshares characteristics with more than one entry.

Suitable applications include: Home printers, Office network printers,Short run digital printers, Commercial print systems, Fabric printers,Pocket printers, Internet WWW printers, Video printers, Medical imaging,Wide format printers, Notebook PC printers, Fax machines, Industrialprinting systems, Photocopiers, Photographic minilabs etc.

The information associated with the aforementioned 11 dimensional matrixare set out in the following tables.

Actuator mechanism (applied only to selected ink drops) ActuatorMechanism Description Advantages Disadvantages Examples Thermal bubbleAn electrothermal heater heats the ink to Large force generated Highpower Canon Bubblejet 1979 above boiling point, transferring Simpleconstruction Ink carrier limited to water Endo et al GB patentsignificant heat to the aqueous ink. A No moving parts Low efficiency2,007,162 bubble nucleates and quickly forms, Fast operation Hightemperatures required Xerox heater-in-pit 1990 expelling the ink. Smallintegrated circuit area High mechanical stress Hawkins et al U.S. Pat.No. The efficiency of the process is low, with required for actuatorUnusual materials required 4,899,181 typically less than 0.05% of theelectrical Large drive transistors Hewlett-Packard TIJ 1982 energy beingtransformed into kinetic energy of the Cavitation causes actuatorfailure Vaught et al U.S. Pat. No. drop. Kogation reduces bubbleformation 4,490,728 Large print heads are difficult to fabricatePiezoelectric A piezoelectric crystal such as lead Low power consumptionVery large area required for actuator Kyser et al U.S. Pat. No.3,946,398 lanthanum zirconate (PZT) is electrically Many ink types canbe used Difficult to integrate with electronics Zoltan U.S. Pat. No.3,683,212 activated, and either expands, shears, or Fast operation Highvoltage drive transistors required 1973 Stemme U.S. Pat. No. bends toapply pressure to the ink, High efficiency Full pagewidth print headsimpractical due to 3,747,120 ejecting drops. actuator size Epson StylusRequires electrical poling in high field Tektronix strengths duringmanufacture IJ04 Electro-strictive An electric field is used to activateLow power consumption Low maximum strain (approx. 0.01%) Seiko Epson,Usui et all JP electrostriction in relaxor materials such Many ink typescan be used Large area required for actuator due to low 253401/96 aslead lanthanum zirconate titanate Low thermal expansion strain IJ04(PLZT) or lead magnesium niobate Electric field strength requiredResponse speed is marginal (~10 μs) (PMN). (approx. 3.5 V/μm) can beHigh voltage drive transistors required generated without difficultyFull pagewidth print heads impractical due to Does not require actuatorsize electrical poling Ferroelectric An electric field is used to inducea Low power consumption Difficult to integrate with electronics IJ04phase transition between the Many ink types can be used Unusualmaterials such as PLZSnT are antiferroelectric (AFE) and ferroelectricFast operation (<1 μs) required (FE) phase. Perovskite materials such asRelatively high longitudinal strain Actuators require a large area tinmodified lead lanthanum zirconate High efficiency titanate (PLZSnT)exhibit large strains of Electric field strength of around 3 V/μm up to1% associated with the AFE to FE can be readily provided phasetransition. Electrostatic plates Conductive plates are separated by aLow power consumption Difficult to operate electrostatic devices in anIJ02, IJ04 compressible or fluid dielectric (usually Many ink types canbe used aqueous environment air). Upon application of a voltage, theFast operation The electrostatic actuator will normally need platesattract each other and displace ink, to be separated from the inkcausing drop ejection. The conductive Very large area required toachieve high plates may be in a comb or honeycomb forces structure, orstacked to increase the High voltage drive transistors may surface areaand therefore the force. be required Full pagewidth print heads are notcompetitive due to actuator size Electrostatic pull A strong electricfield is applied to the Low current consumption High voltage required1989 Saito et al, U.S. Pat. No. on ink ink, whereupon electrostaticattraction Low temperature May be damaged by sparks due to air 4,799,068accelerates the ink towards the print breakdown 1989 Miura et al, U.S.Pat. No. medium. Required field strength increases as the drop 4,810,954size decreases Tone-jet High voltage drive transistors requiredElectrostatic field attracts dust Permanent magnet An electromagnetdirectly attracts a Low power consumption Complex fabrication IJ07, IJ10electro-magnetic permanent magnet, displacing ink and Many ink types canbe used Permanent magnetic material such as causing drop ejection. Rareearth Fast operation Neodymium Iron Boron (NdFeB) required. magnets witha field strength around 1 High efficiency High local currents requiredTesla can be used. Examples are: Easy extension from single Coppermetalization should be used for long Samarium Cobalt (SaCo) and magneticnozzles to pagewidth print heads electromigration lifetime and lowresistivity materials in the neodymium iron boron Pigmented inks areusually infeasible family (NdFeB, NdDyFeBNb, Operating temperaturelimited to the Curie NdDyFeB, etc) temperature (around 540 K) Softmagnetic core A solenoid induced a magnetic field in a Low powerconsumption Complex fabrication IJ01, IJ05, IJ08, IJ10 electro-magneticsoft magnetic core or yoke fabricated Many ink types can be usedMaterials not usually present in a CMOS fab IJ12, IJ14, IJ15, IJ17 froma ferrous material such as Fast operation such as NiFe, CoNiFe, or CoFeare required electroplated iron alloys such as CoNiFe High efficiencyHigh local currents required [1], CoFe, or NiFe alloys. Typically, theEasy extension from single Copper metalization should be used for longsoft magnetic material is in two parts, nozzles to pagewidth print headselectromigration lifetime and low resistivity which are normally heldapart by a Electroplating is required spring. When the solenoid isactuated, High saturation flux density is required (2.0-2.1 the twoparts attract, displacing the ink. T is achievable with CoNiFe [1])Magnetic The Lorenz force acting on a current Low power consumptionForce acts as a twisting motion IJ06, IJ11, IJ13, IJ16 Lorenz forcecarrying wire in a magnetic field is Many ink types can be usedTypically, only a quarter of the solenoid utilized. Fast operationlength provides force in a useful direction This allows the magneticfield to be High efficiency High local currents required suppliedexternally to the print head, for Easy extension from single Coppermetalization should be used for long example with rare earth permanentnozzles to pagewidth print heads electromigration lifetime and lowresistivity magnets. Pigmented inks are usually infeasible Only thecurrent carrying wire need be fabricated on the print-head, simplifyingmaterials requirements. Magneto-striction The actuator uses the giantMany ink types can be used Force acts as a twisting motion Fischenbeck,U.S. Pat. No. magnetostrictive effect of materials such Fast operationUnusual materials such as Terfenol-D are 4,032,929 as Terfenol-D (analloy of terbium, Easy extension from single required IJ25 dysprosiumand iron developed at the nozzles to pagewidth print heads High localcurrents required Naval Ordnance Laboratory, hence Ter- High force isavailable Copper metalization should be used for long Fe-NOL). For bestefficiency, the electromigration lifetime and low resistivity actuatorshould be pre-stressed to Pre-stressing may be required approx. 8 MPa.Surface tension Ink under positive pressure is held in a Low powerconsumption Requires supplementary force to effect drop Silverbrook, EP0771 658 reduction nozzle by surface tension. The surface Simpleconstruction separation A2 and related patent tension of the ink isreduced below the No unusual materials required in Requires special inksurfactants applications bubble threshold, causing the ink tofabrication Speed may be limited by surfactant properties egress fromthe nozzle. High efficiency Easy extension from single nozzles topagewidth print heads Viscosity reduction The ink viscosity is locallyreduced to Simple construction Requires supplementary force to effectdrop Silverbrook, EP 0771 658 select which drops are to be ejected. A Nounusual materials required in separation A2 and related patent viscosityreduction can be achieved fabrication Requires special ink viscosityproperties applications electrothermally with most inks, but Easyextension from single High speed is difficult to achieve special inkscan be engineered for a nozzles to pagewidth print heads Requiresoscillating ink pressure 100:1 viscosity reduction. A high temperaturedifference (typically 80 degrees) is required Acoustic An acoustic waveis generated and Can operate without a nozzle Complex drive circuitry1993 Hadimioglu et al, focussed upon the drop ejection region. plateComplex fabrication EUP 550,192 Low efficiency 1993 Elrod et al, EUPPoor control of drop position 572,220 Poor control of drop volumeThermoelastic bend An actuator which relies upon Low power consumptionEfficient aqueous operation requires a thermal IJ03, IJ09, IJ17, IJ18actuator differential thermal expansion upon Many ink types can be usedinsulator on the hot side IJ19, IJ20, IJ21, IJ22 Joule heating is used.Simple planar fabrication Corrosion prevention can be difficult IJ23,IJ24, IJ27, IJ28 Small integrated circuit area Pigmented inks may beinfeasible, as pigment IJ29, IJ30, IJ31, IJ32 required for each actuatorparticles may jam the bend actuator IJ33, IJ34, IJ35, IJ36 Fastoperation IJ37, IJ38 ,IJ39, IJ40 High efficiency IJ41 CMOS compatiblevoltages and currents Standard MEMS processes can be used Easy extensionfrom single nozzles to pagewidth print heads High CTE A material with avery high coefficient of High force can be generated Requires specialmaterial (e.g. PTFE) IJ09, IJ17, IJ18, IJ20 thermoelastic thermalexpansion (CTE) such as PTFE is a candidate for low Requires a PTFEdeposition process, which is IJ21, IJ22, IJ23, IJ24 actuatorpolytetrafluoroethylene (PTFE) is used. dielectric constant insulationin not yet standard in ULSI fabs IJ27, IJ28, IJ29, IJ30 As high CTEmaterials are usually non- ULSI PTFE deposition cannot be followed withhigh IJ31, IJ42, IJ43, IJ44 conductive, a heater fabricated from a Verylow power consumption temperature (above 350° C.) processing conductivematerial is incorporated. A 50 μm Many ink types can be used Pigmentedinks may be infeasible, as pigment long PTFE bend actuator with Simpleplanar fabrication particles may jam the bend actuator polysiliconheater and 15 mW power Small integrated circuit area input can provide180 μN force and 10 μm required for each actuator deflection. Actuatormotions include: Fast operation Bend High efficiency Push CMOScompatible voltages and Buckle currents Rotate Easy extension fromsingle nozzles to pagewidth print heads Conductive A polymer with a highcoefficient of High force can be generated Requires special materialsdevelopment (High IJ24 polymer thermal expansion (such as PTFE) is Verylow power consumption CTE conductive polymer) thermoelastic doped withconducting substances to Many ink types can be used Requires a PTFEdeposition process, which is actuator increase its conductivity to about3 Simple planar fabrication not yet standard in ULSI fabs orders ofmagnitude below that of Small integrated circuit area PTFE depositioncannot be followed with high copper. The conducting polymer expandsrequired for each actuator temperature (above 350° C.) processing whenresistively heated. Fast operation Evaporation and CVD depositiontechniques Examples of conducting dopants include: High efficiencycannot be used Carbon nanotubes CMOS compatible voltages and Pigmentedinks may be infeasible, as pigment Metal fibers currents particles mayjam the bend actuator Conductive polymers such as doped Easy extensionfrom single polythiophene nozzles to pagewidth print heads Carbongranules Shape memory A shape memory alloy such as TiNi (also High forceis available (stresses of Fatigue limits maximum number of cycles IJ26alloy known as Nitinol - Nickel Titanium alloy hundreds of MPa) Lowstrain (1%) is required to extend fatigue developed at the NavalOrdnance Large strain is available (more resistance Laboratory) isthermally switched than 3%) Cycle rate limited by heat removal betweenits weak martensitic state and its High corrosion resistance Requiresunusual materials (TiNi) high stiffness austenic state. The shape ofSimple construction The latent heat of transformation must be theactuator in its martensitic state is Easy extension from single provideddeformed relative to the austenic shape. nozzles to pagewidth printheads High current operation The shape change causes ejection of a Lowvoltage operation Requires pre-stressing to distort the drop.martensitic state Linear Magnetic Linear magnetic actuators include theLinear Magnetic actuators can be Requires unusual semiconductormaterials IJ12 Actuator Linear Induction Actuator (LIA), Linearconstructed with high thrust, long such as soft magnetic alloys (e.g.CoNiFe [1]) Permanent Magnet Synchronous travel, and high efficiencyusing Some varieties also require permanent Actuator (LPMSA), LinearReluctance planar semiconductor fabrication magnetic materials such asNeodymium iron Synchronous Actuator (LRSA), Linear techniques boron(NdFeB) Switched Reluctance Actuator (LSRA), Long actuator travel isavailable Requires complex multi-phase drive circuitry and the LinearStepper Actuator (LSA). Medium force is available High current operationLow voltage operation

Basic operation mode Operational mode Description AdvantagesDisadvantages Examples Actuator directly pushes ink This is the simplestmode of operation: Simple operation Drop repetition rate is usuallylimited to less Thermal inkjet the actuator directly supplies sufficientNo external fields required than 10 KHz. However, this is notPiezoelectric inkjet kinetic energy to expel the drop. The Satellitedrops can be avoided if fundamental to the method, but is related toIJ01, IJ02, IJ03, IJ04 drop must have a sufficient velocity to dropvelocity is less than 4 m/s the refill method normally used IJ05, IJ06,IJ07, IJ09 overcome the surface tension. Can be efficient, dependingupon All of the drop kinetic energy must be IJ11, IJ12, IJ14, IJ16 theactuator used provided by the actuator IJ20, IJ22, IJ23, IJ24 Satellitedrops usually form if drop velocity is greater than IJ25, IJ26, IJ27,IJ28 4.5 m/s IJ29, IJ30, IJ31, IJ32 IJ33, IJ34, IJ35, IJ36 IJ37, IJ38,IJ39, IJ40 IJ41, IJ42, IJ43, IJ44 Proximity The drops to be printed areselected by Very simple print head fabrication Requires close proximitybetween the print Silverbrook, EP 0771 658 some manner (e.g. thermallyinduced can be used head and the print media or transfer roller A2 andrelated patent surface tension reduction of pressurized The dropselection means does May require two print heads printing alternateapplications ink). Selected drops are separated from not need to providethe energy rows of the image the ink in the nozzle by contact with therequired to separate the drop from Monolithic color print heads aredifficult print medium or a transfer roller. the nozzle Electrostaticpull The drops to be printed are selected by Very simple print headfabrication Requires very high electrostatic field Silverbrook, EP 0771658 on ink some manner (e.g. thermally induced can be used Electrostaticfield for small nozzle sizes is A2 and related patent surface tensionreduction of pressurized The drop selection means does above airbreakdown applications ink). Selected drops are separated from not needto provide the energy Electrostatic field may attract dust Tone-Jet theink in the nozzle by a strong electric required to separate the dropfrom field. the nozzle Magnetic pull on The drops to be printed areselected by Very simple print head fabrication Requires magnetic inkSilverbrook, EP 0771 658 ink some manner (e.g. thermally induced can beused Ink colors other than black are difficult A2 and related patentapplications surface tension reduction of pressurized The drop selectionmeans does Requires very high magnetic fields ink). Selected drops areseparated from not need to provide the energy the ink in the nozzle by astrong required to separate the drop from magnetic field acting on themagnetic the nozzle ink. Shutter The actuator moves a shutter to blockink High speed (>50 KHz) operation Moving parts are required IJ13, IJ17,IJ21 flow to the nozzle. The ink pressure is can be achieved due toreduced Requires ink pressure modulator pulsed at a multiple of the dropejection refill time Friction and wear must be considered frequency.Drop timing can be very accurate Stiction is possible The actuatorenergy can be very low Shuttered grill The actuator moves a shutter toblock ink Actuators with small travel can be used Moving parts arerequired IJ08, IJ15, IJ18, IJ19 flow through a grill to the nozzle. TheActuators with small force can be used Requires ink pressure modulatorshutter movement need only be equal to High speed (>50 KHz) operationFriction and wear must be considered the width of the grill holes. canbe achieved Stiction is possible Pulsed magnetic A pulsed magnetic fieldattracts an ‘ink Extremely low energy operation Requires an externalpulsed magnetic field IJ10 pull on ink pusher pusher’ at the dropejection frequency. is possible Requires special materials for both theAn actuator controls a catch, which No heat dissipation problemsactuator and the ink pusher prevents the ink pusher from moving Complexconstruction when a drop is not to be ejected.

Auxiliary mechanism (applied to all nozzles) Auxiliary MechanismDescription Advantages Disadvantages Examples None The actuator directlyfires the ink drop, Simplicity of construction Drop ejection energy mustbe supplied by Most inkjets, including and there is no external field orother Simplicity of operation individual nozzle actuator piezoelectricand thermal mechanism required. Small physical size bubble. IJ01-IJ07,IJ09, IJ11 IJ12, IJ14, IJ20, IJ22 IJ23-IJ45 Oscillating ink The inkpressure oscillates, providing Oscillating ink pressure can Requiresexternal ink pressure oscillator Silverbrook, EP 0771 658 pressure muchof the drop ejection energy. The provide a refill pulse, allowing Inkpressure phase and amplitude must be A2 and related patent (includingacoustic stimulation) actuator selects which drops are to be higheroperating speed carefully controlled applications fired by selectivelyblocking or enabling The actuators may operate with Acoustic reflectionsin the ink chamber must IJ08, IJ13, IJ15, IJ17 nozzles. The ink pressureoscillation may much lower energy be designed for IJ18, IJ19, IJ21 beachieved by vibrating the print head, Acoustic lenses can be used to orpreferably by an actuator in the ink focus the sound on the nozzlessupply. Media proximity The print head is placed in close Low powerPrecision assembly required Silverbrook, EP 0771 658 proximity to theprint medium. Selected High accuracy Paper fibers may cause problems A2and related patent drops protrude from the print head Simple print headconstruction Cannot print on rough substrates applications further thanunselected drops, and contact the print medium. The drop soaks into themedium fast enough to cause drop separation. Transfer roller Drops areprinted to a transfer roller High accuracy Bulky Silverbrook, EP 0771658 instead of straight to the print medium. A Wide range of printsubstrates can Expensive A2 and related patent transfer roller can alsobe used for be used Complex construction applications proximity dropseparation. Ink can be dried on the transfer Tektronix hot melt rollerpiezoelectric inkjet Any of the IJ series Electrostatic An electricfield is used to accelerate Low power Field strength required forseparation of small Silverbrook, EP 0771 658 selected drops towards theprint medium. Simple print head construction drops is near or above airbreakdown A2 and related patent applications Tone-Jet Direct magnetic Amagnetic field is used to accelerate Low power Requires magnetic inkSilverbrook, EP 0771 658 field selected drops of magnetic ink towardsSimple print head construction Requires strong magnetic field A2 andrelated patent the print medium. applications Cross magnetic The printhead is placed in a constant Does not require magnetic Requires externalmagnet IJ06, IJ16 field magnetic field. The Lorenz force in a materialsto be integrated in the Current densities may be high, resulting incurrent carrying wire is used to move the print head manufacturingprocess electromigration problems actuator. Pulsed magnetic A pulsedmagnetic field is used to Very low power operation is Complex print headconstruction IJ10 field cyclically attract a paddle, which pushespossible Magnetic materials required in print head on the ink. A smallactuator moves a Small print head size catch, which selectively preventsthe paddle from moving.

Actuator amplification or modification method Actuator amplificationDescription Advantages Disadvantages Examples None No actuatormechanical amplification is Operational simplicity Many actuatormechanisms have insufficient Thermal Bubble Inkjet used. The actuatordirectly drives the travel, or insufficient force, to efficiently driveIJ01, IJ02, IJ06, IJ07 drop ejection process. the drop ejection processIJ16, IJ25, IJ26 Differential An actuator material expands more onProvides greater travel in a High stresses are involved Piezoelectricexpansion bend one side than on the other. The reduced print head areaCare must be taken that the materials do not IJ03, IJ09, IJ17-IJ24actuator expansion may be thermal, piezoelectric, The bend actuatorconverts a high delaminate IJ27, IJ29-IJ39, IJ42, magnetostrictive, orother mechanism, force low travel actuator Residual bend resulting fromhigh temperature IJ43, IJ44 mechanism to high travel, lower force orhigh stress during formation mechanism. Transient bend A trilayer bendactuator where the two Very good temperature stability High stresses areinvolved IJ40, IJ41 actuator outside layers are identical. This cancelsHigh speed, as a new drop can be Care must be taken that the materialsdo not bend due to ambient temperature and fired before heat dissipatesdelaminate residual stress. The actuator only Cancels residual stress ofresponds to transient heating of one side or the other. formationActuator stack A series of thin actuators are stacked. Increased travelIncreased fabrication complexity Some piezoelectric ink jets IJ04 Thiscan be appropriate where actuators Reduced drive voltage Increasedpossibility of short circuits due to require high electric fieldstrength, such pinholes as electrostatic and piezoelectric actuators.Multiple actuators Multiple smaller actuators are used Increases theforce available from Actuator forces may not add linearly, reducingefficiency IJ12, IJ13, IJ18, IJ20 simultaneously to move the ink. Eachan actuator IJ22, IJ28, IJ42, IJ43 actuator need provide only a portionof Multiple actuators can be the force required. positioned to controlink flow accurately Linear Spring A linear spring is used to transform aMatches low travel actuator with Requires print head area for the springIJ15 motion with small travel and high force higher travel requirementsinto a longer travel, lower force motion. Non-contact method of motiontransformation Reverse spring The actuator loads a spring. When theBetter coupling to the ink Fabrication complexity IJ05, IJ11 actuator isturned off, the spring releases. High stress in the spring This canreverse the force/distance curve of the actuator to make it compatiblewith the force/time requirements of the drop ejection. Coiled actuator Abend actuator is coiled to provide Increases travel Generally restrictedto planar implementations IJ17, IJ21, IJ34, IJ35 greater travel in areduced integrated Reduces integrated circuit area due to extremefabrication difficulty in other circuit area. Planar implementations areorientations. relatively easy to fabricate. Flexure bend A bend actuatorhas a small region near Simple means of increasing travel Care must betaken not to exceed the elastic IJ10, IJ19, IJ33 actuator the fixturepoint, which flexes much of a bend actuator limit in the flexure areamore readily than the remainder of the Stress distribution is veryuneven actuator. The actuator flexing is Difficult to accurately modelwith finite effectively converted from an even element analysis coilingto an angular bend, resulting in greater travel of the actuator tip.Gears Gears can be used to increase travel at Low force, low travelactuators Moving parts are required IJ13 the expense of duration.Circular gears, can be used Several actuator cycles are required rackand pinion, ratchets, and other Can be fabricated using standard Morecomplex drive electronics gearing methods can be used. surface MEMSprocesses Complex construction Friction, friction, and wear are possibleCatch The actuator controls a small catch. The Very low actuator energyComplex construction IJ10 catch either enables or disables Very smallactuator size Requires external force movement of an ink pusher that isUnsuitable for pigmented inks controlled in a bulk manner. Buckle plateA buckle plate can be used to change a Very fast movement achievableMust stay within elastic limits of the materials S. Hirata et al, “AnInk-jet slow actuator into a fast motion. It can for long device lifeHead . . . ”, Proc. IEEE also convert a high force, low travel Highstresses involved MEMS, February 1996, pp actuator into a high travel,medium force Generally high power requirement 418-423. motion. IJ18,IJ27 Tapered magnetic A tapered magnetic pole can increase Linearizesthe magnetic Complex construction IJ14 pole travel at the expense offorce. force/distance curve Lever A lever and fulcrum is used totransform Matches low travel actuator with High stress around thefulcrum IJ32, IJ36, IJ37 a motion with small travel and high forcehigher travel requirements into a motion with longer travel and Fulcrumarea has no linear lower force. The lever can also reverse movement, andcan be used for a the direction of travel. fluid seal Rotary impellerThe actuator is connected to a rotary High mechanical advantage Complexconstruction IJ28 impeller. A small angular deflection of The ratio offorce to travel of the Unsuitable for pigmented inks the actuatorresults in a rotation of the actuator can be matched to the impellervanes, which push the ink nozzle requirements by varying againststationary vanes and out of the the number of impeller vanes nozzle.Acoustic lens A refractive or diffractive (e.g. zone No moving partsLarge area required 1993 Hadimioglu et al, plate) acoustic lens is usedto concentrate Only relevant for acoustic ink jets EUP 550,192 soundwaves. 1993 Elrod et al, EUP 572,220 Sharp conductive A sharp point isused to concentrate an Simple construction Difficult to fabricate usingstandard VLSI Tone-jet point electrostatic field. processes for asurface ejecting ink-jet Only relevant for electrostatic ink jets

Actuator motion Actuator motion Description Advantages DisadvantagesExamples Volume expansion The volume of the actuator changes, Simpleconstruction in the case of thermal ink jet High energy is typicallyrequired to achieve Hewlett-Packard Thermal pushing the ink in alldirections. volume expansion. This leads to thermal Inkjet stress,cavitation, and kogation in thermal ink Canon Bubblejet jetimplementations Linear, normal to The actuator moves in a directionnormal Efficient coupling to ink drops High fabrication complexity maybe required IJ01, IJ02, IJ04, IJ07 integrated circuit to the print headsurface. The nozzle is ejected normal to the surface to achieveperpendicular motion IJ11, IJ14 surface typically in the line ofmovement. Linear, parallel to The actuator moves parallel to the printSuitable for planar fabrication Fabrication complexity IJ12, IJ13, IJ15,IJ33, integrated circuit head surface. Drop ejection may still beFriction IJ34, IJ35, IJ36 surface normal to the surface. StictionMembrane push An actuator with a high force but small The effective areaof the actuator Fabrication complexity 1982 Howkins U.S. Pat. No. areais used to push a stiff membrane that becomes the membrane area Actuatorsize 4,459,601 is in contact with the ink. Difficulty of integration ina VLSI process Rotary The actuator causes the rotation of some Rotarylevers may be used to Device complexity IJ05, IJ08, IJ13, IJ28 element,such a grill or impeller increase travel May have friction at a pivotpoint Small integrated circuit area requirements Bend The actuator bendswhen energized. This A very small change in Requires the actuator to bemade from at least 1970 Kyser et al U.S. Pat. No. may be due todifferential thermal dimensions can be converted to a two distinctlayers, or to have a thermal 3,946,398 expansion, piezoelectricexpansion, large motion. difference across the actuator 1973 Stemme U.S.Pat. No. magnetostriction, or other form of 3,747,120 relativedimensional change. IJ03, IJ09, IJ10, IJ19 IJ23, IJ24, IJ25, IJ29 IJ30,IJ31, IJ33, IJ34 IJ35 Swivel The actuator swivels around a centralAllows operation where the net Inefficient coupling to the ink motionIJ06 pivot. This motion is suitable where there linear force on thepaddle is zero are opposite forces applied to opposite Small integratedcircuit area sides of the paddle, e.g. Lorenz force. requirementsStraighten The actuator is normally bent, and Can be used with shapememory Requires careful balance of stresses to ensure IJ26, IJ32straightens when energized. alloys where the austenic phase is that thequiescent bend is accurate planar Double bend The actuator bends in onedirection when One actuator can be used to Difficult to make the dropsejected by both IJ36, IJ37, IJ38 one element is energized, and bends thepower two nozzles. bend directions identical. other way when anotherelement is Reduced integrated circuit size. A small efficiency losscompared to energized. Not sensitive to ambient equivalent single bendactuators. temperature Shear Energizing the actuator causes a shear Canincrease the effective travel Not readily applicable to other actuator1985 Fishbeck U.S. Pat. No. motion in the actuator material. ofpiezoelectric actuators mechanisms 4,584,590 Radial constriction Theactuator squeezes an ink reservoir, Relatively easy to fabricate singleHigh force required 1970 Zoltan U.S. Pat. No. forcing ink from aconstricted nozzle. nozzles from glass tubing as Inefficient 3,683,212macroscopic structures Difficult to integrate with VLSI processesCoil/uncoil A coiled actuator uncoils or coils more Easy to fabricate asa planar VLSI Difficult to fabricate for non-planar devices IJ17, IJ21,IJ34, IJ35 tightly. The motion of the free end of the process Poorout-of-plane stiffness actuator ejects the ink. Small area required,therefore low cost Bow The actuator bows (or buckles) in the Canincrease the speed of travel Maximum travel is constrained IJ16, IJ18,IJ27 middle when energized. Mechanically rigid High force requiredPush-Pull Two actuators control a shutter. One The structure is pinnedat both Not readily suitable for inkjets which directly IJ18 actuatorpulls the shutter, and the other ends, so has a high out-of-plane pushthe ink pushes it. rigidity Curl inwards A set of actuators curl inwardsto reduce Good fluid flow to the region Design complexity IJ20, IJ42 thevolume of ink that they enclose. behind the actuator increasesefficiency Curl outwards A set of actuators curl outwards, Relativelysimple construction Relatively large integrated circuit area IJ43pressurizing ink in a chamber surrounding the actuators, and expellingink from a nozzle in the chamber. Iris Multiple vanes enclose a volumeof ink. High efficiency High fabrication complexity IJ22 Thesesimultaneously rotate, reducing Small integrated circuit area Notsuitable for pigmented inks the volume between the vanes. Acousticvibration The actuator vibrates at a high frequency. The actuator can bephysically Large area required for efficient operation at 1993Hadimioglu et al, distant from the ink useful frequencies EUP 550,192Acoustic coupling and crosstalk 1993 Elrod et al, EUP Complex drivecircuitry 572,220 Poor control of drop volume and position None Invarious ink jet designs the actuator does not move. No moving partsVarious other tradeoffs are required to Silverbrook, EP 0771 658 A2 andeliminate moving parts related patent applications Tone-jet

Nozzle refill method Nozzle refill method Description Advantages Surfacetension After the actuator is energized, it Fabrication simplicitytypically returns rapidly to its normal Operational simplicity position.This rapid return sucks in air through the nozzle opening. The inksurface tension at the nozzle then exerts a small force restoring themeniscus to a minimum area. Shuttered Ink to the nozzle chamber isprovided at High speed oscillating ink pressure a pressure thatoscillates at twice the Low actuator energy, as the drop ejectionfrequency. When a drop is actuator need only open or close to beejected, the shutter is opened for 3 the shutter, instead of ejectingthe half cycles: drop ejection, actuator ink drop return, and refill.Refill actuator After the main actuator has ejected a High speed, as thenozzle is drop a second (refill) actuator is actively refilledenergized. The refill actuator pushes ink into the nozzle chamber. Therefill actuator returns slowly, to prevent its return from emptying thechamber again. Positive ink The ink is held a slight positive pressure.High refill rate, therefore a high pressure After the ink drop isejected, the nozzle drop repetition rate is possible chamber fillsquickly as surface tension and ink pressure both operate to refill thenozzle. Nozzle refill method Disadvantages Examples Surface tension Lowspeed Thermal inkjet Surface tension force relatively smallPiezoelectric inkjet compared to actuator force IJ01-IJ07, IJ10-IJ14Long refill time usually dominates the total repetition rate IJ16, IJ20,IJ22-IJ45 Shuttered Requires common ink pressure oscillator IJ08, IJ13,IJ15, IJ17 oscillating ink pressure May not be suitable for pigmentedinks IJ18, IJ19, IJ21 Refill actuator Requires two independent actuatorsper nozzle IJ09 Positive ink Surface spill must be preventedSilverbrook, EP 0771 658 pressure Highly hydrophobic print head surfacesare A2 and related patent required applications Alternative for:IJ01-IJ07, IJ10-IJ14 IJ16, IJ20, IJ22-IJ45

Method of restricting back-flow through inlet Inlet back-flowrestriction method Description Advantages Disadvantages Examples Longinlet channel The ink inlet channel to the nozzle Design simplicityRestricts refill rate Thermal inkjet chamber is made long and relativelyOperational simplicity May result in a relatively large integratedPiezoelectric inkjet narrow, relying on viscous drag to reduce inletback-flow. Reduces crosstalk circuit area IJ42, IJ43 Only partiallyeffective Positive ink pressure The ink is under a positive pressure, sothat in the Drop selection and separation Requires a method (such as anozzle rim or Silverbrook, EP 0771 658 quiescent state some of the inkdrop already protrudes forces can be reduced effective hydrophobizing,or both) to prevent A2 and related patent applications from the nozzle.This reduces the pressure in the Fast refill time flooding of theejection surface of the print Possible operation of the following:nozzle chamber which is required to eject a certain head. IJ01–IJ07,IJ09–IJ12 volume of ink. The reduction in chamber pressure results IJ14,IJ16, IJ20, IJ22, in a reduction in ink pushed out through the inlet.IJ23–IJ34, IJ36–IJ41 IJ44 Baffle One or more baffles are placed in theinlet ink flow. The refill rate is not as restricted Design complexityHP Thermal Ink Jet When the actuator is energized, the rapid inkmovement as the long inlet method. May increase fabrication complexity(e.g. Tektronix piezoelectric ink creates eddies which restrict the flowthrough the inlet. Reduces crosstalk Tektronix hot melt Piezoelectricprint heads). jet The slower refill process is unrestricted, and doesnot result in eddies. Flexible flap restricts inlet In this methodrecently disclosed by Significantly reduces back-flow Not applicable tomost inkjet configurations Canon Canon, the expanding actuator (bubble)for edge-shooter thermal ink jet Increased fabrication complexity pusheson a flexible flap that restricts the devices Inelastic deformation ofpolymer flap results inlet. in creep over extended use Inlet filter Afilter is located between the ink inlet and the Additional advantage ofink Restricts refill rate IJ04, IJ12, IJ24, IJ27 nozzle chamber. Thefilter has a multitude of small holes filtration May result in complexconstruction IJ29, IJ30 or slots, restricting ink flow. The filter alsoInk filter may be fabricated with removes particles which may block thenozzle. no additional process steps Small inlet compared to nozzle Theink inlet channel to the nozzle Design simplicity Restricts refill rateIJ02, IJ37, IJ44 chamber has a substantially smaller cross May result ina relatively large integrated section than that of the nozzle, resultingin easier circuit area ink egress out of the nozzle than out of theinlet. Only partially effective Inlet shutter A secondary actuatorcontrols the position of a shutter, Increases speed of the ink-jet printRequires separate refill actuator and drive IJ09 closing off the inkinlet when the main actuator is head operation circuit energized. Theinlet is located behind the The method avoids the problem of inletBack-flow problem is eliminated Requires careful design to minimize theIJ01, IJ03, IJ05, IJ06 ink-pushing surface back-flow by arranging theink-pushing negative pressure behind the paddle IJ07, IJ10, IJ11, IJ14surface of the actuator between the inlet IJ16, IJ22, IJ23, IJ25 and thenozzle. IJ28, IJ31, IJ32, IJ33 IJ34, IJ35, IJ36, IJ39 IJ40, IJ41 Part ofthe actuator moves to The actuator and a wall of the ink Significantreductions in back- Small increase in fabrication complexity IJ07, IJ20,IJ26, IJ38 shut off the inlet chamber are arranged so that the motionflow can be achieved of the actuator closes off the inlet. Compactdesigns possible Nozzle actuator does not result In some configurationsof ink jet, there is Ink back-flow problem is None related to inkback-flow on actuation Silverbrook, EP 0771 658 in ink back-flow noexpansion or movement of an actuator eliminated A2 and related patentwhich may cause ink back-flow through applications the inlet. Valve-jetTone-jet IJ08, IJ13, IJ15, IJ17 IJ18, IJ19, IJ21

Nozzle Clearing Method Nozzle Clearing method Description AdvantagesDisadvantages Examples Normal nozzle firing All of the nozzles are firedperiodically, before the No added complexity on the print head May notbe sufficient to displace dried ink Most ink jet systems ink has achance to dry. When not in use the nozzles IJ01–IJ07, IJ09–IJ12 aresealed (capped) against air. The nozzle firing is usually IJ14, IJ16,IJ20, IJ22 performed during a special clearing cycle, after firstIJ23–IJ34, IJ36–IJ45 moving the print head to a cleaning station. Extrapower to ink heater In systems which heat the ink, but do not Can behighly effective if the Requires higher drive voltage for clearingSilverbrook, EP 0771 658 boil it under normal situations, nozzle heateris adjacent to the nozzle May require larger drive transistors A2 andrelated patent clearing can be achieved by over- applications poweringthe heater and boiling ink at the nozzle. Rapid succession The actuatoris fired in rapid succession. Does not require extra drive Effectivenessdepends substantially upon the May be used with: of actuator pulses Insome configurations, this may cause circuits on the print headconfiguration of the inkjet nozzle IJ01–IJ07, IJ09–IJ11 heat build-up atthe nozzle which boils Can be readily controlled and IJ14, IJ16, IJ20,IJ22 the ink, clearing the nozzle. In other initiated by digital logicIJ23–IJ25, IJ27–IJ34 IJ36–IJ45 situations, it may cause sufficientvibrations to dislodge clogged nozzles. Extra power to ink Where anactuator is not normally driven A simple solution where applicable Notsuitable where there is a hard limit to May be used with: pushingactuator to the limit of its motion, nozzle clearing actuator movementIJ03, IJ09, IJ16, IJ20 may be assisted by providing an IJ23, IJ24, IJ25,IJ27 enhanced drive signal to the actuator. IJ29, IJ30, IJ31, IJ32 IJ39,IJ40, IJ41, IJ42 IJ43, IJ44, IJ45 Acoustic resonance An ultrasonic waveis applied to the ink chamber. This A high nozzle clearing capabilityHigh implementation cost if system does not IJ08, IJ13, IJ15, IJ17 waveis of an appropriate amplitude and frequency can be achieved alreadyinclude an acoustic actuator IJ18, IJ19, IJ21 to cause sufficient forceat the nozzle to clear blockages. May be implemented at very low This iseasiest to achieve if the ultrasonic wave cost in systems which alreadyis at a resonant frequency of the ink cavity. include acoustic actuatorsNozzle clearing plate A microfabricated plate is pushed against Canclear severely clogged nozzles Accurate mechanical alignment is requiredSilverbrook, EP 0771 658 the nozzles. The plate has a post for Movingparts are required A2 and related patent every nozzle. The array ofposts There is risk of damage to the nozzles applications Accuratefabrication is required Ink pressure pulse The pressure of the ink istemporarily May be effective where other Requires pressure pump or otherpressure May be used with all IJ increased so that ink streams from allof methods cannot be used actuator series ink jets the nozzles. This maybe used in Expensive conjunction with actuator energizing. Wasteful ofink Print head wiper A flexible ‘blade’ is wiped across the Effectivefor planar print head Difficult to use if print head surface is non-Many ink jet systems print head surface. The blade is usually surfacesplanar or very fragile fabricated from a flexible polymer, e.g. Low costRequires mechanical parts rubber or synthetic elastomer. Blade can wearout in high volume print systems Separate ink A separate heater isprovided at the Can be effective where other Fabrication complexity Canbe used with many IJ boiling heater nozzle although the normal drope-ection nozzle clearing methods cannot series ink jets mechanism doesnot require it. The be used heaters do not require individual drive Canbe implemented at no additional circuits, as many nozzles can be clearedcost in some inkjet configurations simultaneously, and no imaging isrequired.

Nozzle plate construction Nozzle plate construction DescriptionAdvantages Disadvantages Examples Electroformed nickel A nozzle plate isseparately fabricated Fabrication simplicity High temperatures andpressures are required Hewlett Packard Thermal Inkjet from electroformednickel, and bonded to bond nozzle plate to the print head integratedcircuit. Minimum thickness constraints Differential thermal expansionLaser ablated or drilled polymer Individual nozzle holes are ablated byan No masks required Each hole must be individually formed CanonBubblejet intense UV laser in a nozzle plate, which Can be quite fastSpecial equipment required 1988 Sercel et al., SPIE, is typically apolymer such as polyimide Some control over nozzle profile Slow wherethere are many thousands of Vol. 998 Excimer Beam or polysulphone ispossible nozzles per print head Applications, pp. 76–83 Equipmentrequired is relatively May produce thin burrs at exit holes 1993Watanabe et al., U.S. Pat. No. 5,208,604 low cost Silicon micro-machinedA separate nozzle plate is micro- High accuracy is attainable Two partconstruction K. Bean, IEEE machined from single crystal silicon, Highcost Transactions on Electron Devices, Vol. ED-25, and bonded to theprint head wafer. Requires precision alignment No. 10, 1978, pp1185–1195 Nozzles may be clogged by adhesive Xerox 1990 Hawkins et al.,U.S. Pat. No. 4,899,181 Glass capillaries Fine glass capillaries aredrawn from No expensive equipment required Very small nozzle sizes aredifficult to form 1970 Zoltan U.S. Pat. No. 3,683,212 glass tubing. Thismethod has been used Simple to make single nozzles Not suited for massproduction for making individual nozzles, but is difficult to use forbulk manufacturing of print heads with thousands of nozzles. Monolithic,surface micro- The nozzle plate is deposited as a layer High accuracy(<1 μm) Requires sacrificial layer under the nozzle Silverbrook, EP 0771658 machined using VLSI using standard VLSI deposition Monolithic plateto form the nozzle chamber A2 and related patent lithographic processestechniques. Nozzles are etched in the Low cost Surface may be fragile tothe touch applications nozzle plate using VLSI lithography and Existingprocesses can be used IJ01, IJ02, IJ04, IJ11 etching. IJ12, IJ17, IJ18,IJ20 IJ22, IJ24, IJ27, IJ28 IJ29, IJ30, IJ31, IJ32 IJ33, IJ34, IJ36,IJ37 IJ38, IJ39, IJ40, IJ41 IJ42, IJ43, IJ44 Monolithic, etched Thenozzle plate is a buried etch stop in High accuracy (<1 μm) Requireslong etch times IJ03, IJ05, IJ06, IJ07 through substrate the wafer.Nozzle chambers are etched in Monolithic Requires a support wafer IJ08,IJ09, IJ10, IJ13 the front of the wafer, and the wafer is Low cost IJ14,IJ15, IJ16, IJ19 thinned from the back side. Nozzles are No differentialexpansion IJ21, IJ23, IJ25, IJ26 then etched in the etch stop layer. Nonozzle plate Various methods have been tried to No nozzles to becomeclogged Difficult to control drop position accurately Ricoh 1995 Sekiyaet al eliminate the nozzles entirely, to prevent Crosstalk problems U.S.Pat. No. 5,412,413 nozzle clogging. These include thermal 1993Hadimioglu et al bubble mechanisms and acoustic lens EUP 550,192mechanisms 1993 Elrod et al EUP 572,220 Trough Each drop ejector has atrough through which Reduced manufacturing complexity Drop firingdirection is sensitive to wicking. IJ35 a paddle moves. There is nonozzle plate. Monolithic Nozzle slit instead The elimination of nozzleholes and No nozzles to become clogged Difficult to control dropposition accurately 1989 Saito et al U.S. Pat. No. 4,799,068 ofindividual replacement by a slit encompassing Crosstalk problems nozzlesmany actuator positions reduces nozzle clogging, but increases crosstalkdue to ink surface waves

Drop ejection direction Ejection direction Description AdvantagesDisadvantages Examples Edge Ink flow is along the surface of the Simpleconstruction Nozzles limited to edge Canon Bubblejet 1979 (‘edgeintegrated circuit, and ink drops are No silicon etching required Highresolution is difficult Endo et al GB patent shooter’) ejected from theintegrated circuit edge. Good heat sinking via substrate Fast colorprinting requires 2,007,162 Mechanically strong one print head per colorXerox heater-in-pit Ease of integrated circuit handing 1990 Hawkins etal U.S. Pat. No. 4,899,181 Tone-jet Surface Ink flow is along thesurface of the No bulk silicon etching required Maximum ink flow isHewlett-Packard TIJ (‘roof shooter’) integrated circuit, and ink dropsare Silicon can make an effective heat severely restricted 1982 Vaughtet al ejected from the integrated circuit sink U.S. Pat. No. surface,normal to the plane of the Mechanical strength 4,490,728 IJ02,integrated circuit. IJ11, IJ12, IJ20 IJ22 Through Ink flow is throughthe integrated circuit, High ink flow Requires bulk silicon etchingSilverbrook, integrated and ink drops are ejected from the frontSuitable for pagewidth print EP 0771 658 A2 circuit, forward surface ofthe integrated circuit. High nozzle packing density and related patent(‘up shooter’) therefore low manufacturing cost applications IJ04, IJ17,IJ18, IJ24 IJ27–IJ45 Through Ink flow is through the integrated circuit,High ink flow Requires wafer thinning IJ01, IJ03, IJ05, IJ06 integratedand ink drops are ejected from the rear Suitable for pagewidth printRequires special handling IJ07, IJ08, IJ09, IJ10 circuit, reversesurface of the integrated circuit. High nozzle packing density duringmanufacture IJ13, IJ14, IJ15, IJ16 (‘down therefore low manufacturingcost IJ19, IJ21, IJ23, IJ25 shooter’) IJ26 Through Ink flow is throughthe actuator, which is Suitable for piezoelectric print Pagewidth printheads Epson Stylus actuator not fabricated as part of the same headsrequire several thousand Tektronix hot melt substrate as the drivetransistors. connections to drive circuits piezoelectric ink jets Cannotbe manufactured in standard CMOS fabs Complex assembly required

Ink type Ink type Description Advantages Disadvantages Examples Aqueous,Water based ink which typically Environmentally friendly Slow dryingMost existing inkjets dye contains: water, dye, surfactant, No odorCorrosive All IJ series ink jets humectant, and biocide. Bleeds on paperSilverbrook, EP 0771 658 Modern ink dyes have high water- Maystrikethrough A2 and related patent fastness, light fastness Cocklespaper applications Aqueous, Water based ink which typicallyEnvironmentally friendly Slow drying IJ02, IJ04, IJ21, IJ26 pigmentcontains: water, pigment, surfactant, No odor Corrosive IJ27, IJ30humectant, and biocide. Reduced bleed Pigment may clog nozzlesSilverbrook, EP 0771 658 Pigments have an advantage in reduced Reducedwicking Pigment may clog actuator A2 and related patent bleed, wickingand strikethrough. Reduced strikethrough mechanisms applications Cocklespaper Piezoelectric ink-jets Thermal ink jets (with significantrestrictions) Methyl Ethyl MEK is a highly volatile solvent used forVery fast drying Odorous All IJ series ink jets Ketone industrialprinting on difficult surfaces Prints on various substrates suchFlammable (MEK) such as aluminum cans. as metals and plastics AlcoholAlcohol based inks can be used where Fast drying Slight odor All IJseries ink jets (ethanol, the printer must operate at temperaturesOperates at sub-freezing Flammable 2-butanol, below the freezing pointof water. An temperatures and others) example of this is in-cameraconsumer Reduced paper cockle photographic printing. Low cost Phase Theink is solid at room temperature, and No drying time—ink instantly Highviscosity Tektronix hot melt change is melted in the print head beforejetting. freezes on the print medium Printed ink typically haspiezoelectric ink jets (hot melt) Hot melt inks are usually wax based,Almost any print medium can be a ‘waxy’ feel 1989 Nowak U.S. Pat. No.with a melting point around 80° C. After used Printed pages may ‘block’4,820,346 jetting the ink freezes almost instantly No paper cockleoccurs Ink temperature may be above All IJ series ink jets uponcontacting the print medium or a No wicking occurs the curie point oftransfer roller. No bleed occurs permanent magnets No strikethroughoccurs Ink heaters consume power Long warm-up time Oil Oil based inksare extensively used in High solubility medium for High viscosity: thisis a All IJ series ink jets offset printing. They have advantages insome dyes significant limitation improved characteristics on paper Doesnot cockle paper for use in inkjets, which (especially no wicking orcockle). Oil Does not wick through paper usually require a low solubledies and pigments are required. viscosity. Some short chain andmulti-branched oils have a sufficiently low viscosity. Slow dryingMicro- A microemulsion is a stable, self forming Stops ink bleedViscosity higher than water All IJ series ink jets emulsion emulsion ofoil, water, and surfactant. High dye solubility Cost is slightly higherthan The characteristic drop size is less than Water, oil, andamphiphilic water based ink 100 nm, and is determined by the solubledies can be used High surfactant concentration preferred curvature ofthe surfactant. Can stabilize pigment required (around 5%) suspensionsInk Jet Printing

A large number of new forms of ink jet printers have been developed tofacilitate alternative ink jet technologies for the image processing anddata distribution system. Various combinations of ink jet devices can beincluded in printer devices incorporated as part of the presentinvention. Australian Provisional Patent Applications relating to theseink jets which are specifically incorporated by cross reference. Theserial numbers of respective corresponding US patent applications arealso provided for the sake of convenience.

Australian U.S. Pat. No./ Provisional Patent Application Number FilingDate Title and Filing Date PO8066 15-Jul-97 Image Creation Method andApparatus (IJ01) 6,227,652 (Jul. 10, 1998) PO8072 15-Jul-97 ImageCreation Method and Apparatus (IJ02) 6,213,588 (Jul. 10, 1998) PO804015-Jul-97 Image Creation Method and Apparatus (IJ03) 6,213,589 (Jul. 10,1998) PO8071 15-Jul-97 Image Creation Method and Apparatus (IJ04)6,231,163 (Jul. 10, 1998) PO8047 15-Jul-97 Image Creation Method andApparatus (IJ05) 6,247,795 (Jul. 10, 1998) PO8035 15-Jul-97 ImageCreation Method and Apparatus (IJ06) 6,394,581 (Jul. 10, 1998) PO804415-Jul-97 Image Creation Method and Apparatus (IJ07) 6,244,691 (Jul. 10,1998) PO8063 15-Jul-97 Image Creation Method and Apparatus (IJ08)6,257,704 (Jul. 10, 1998) PO8057 15-Jul-97 Image Creation Method andApparatus (IJ09) 6,416,168 (Jul. 10, 1998) PO8056 15-Jul-97 ImageCreation Method and Apparatus (IJ10) 6,220,694 (Jul. 10, 1998 PO806915-Jul-97 Image Creation Method and Apparatus (IJ11) 6,257,705 (Jul. 10,1998 PO8049 15-Jul-97 Image Creation Method and Apparatus (IJ12)6,247,794 (Jul. 10, 1998 PO8036 15-Jul-97 Image Creation Method andApparatus (IJ13) 6,234,610 (Jul. 10, 1998 PO8048 15-Jul-97 ImageCreation Method and Apparatus (IJ14) 6,247,793 (Jul. 10, 1998 PO807015-Jul-97 Image Creation Method and Apparatus (IJ15) 6,264,306 (Jul. 10,1998 PO8067 15-Jul-97 Image Creation Method and Apparatus (IJ16)6,241,342 (Jul. 10, 1998 PO8001 15-Jul-97 Image Creation Method andApparatus (IJ17) 6,247,792 (Jul. 10, 1998 PO8038 15-Jul-97 ImageCreation Method and Apparatus (IJ18) 6,264,307 (Jul. 10, 1998 PO803315-Jul-97 Image Creation Method and Apparatus (IJ19) 6,254,220 (Jul. 10,1998 PO8002 15-Jul-97 Image Creation Method and Apparatus (IJ20)6,234,611 (Jul. 10, 1998 PO8068 15-Jul-97 Image Creation Method andApparatus (IJ21) 6,302,528 (Jul. 10, 1998 PO8062 15-Jul-97 ImageCreation Method and Apparatus (IJ22) 6,283,582 (Jul. 10, 1998 PO803415-Jul-97 Image Creation Method and Apparatus (IJ23) 6,239,821 (Jul. 10,1998 PO8039 15-Jul-97 Image Creation Method and Apparatus (IJ24)6,338,547 (Jul. 10, 1998 PO8041 15-Jul-97 Image Creation Method andApparatus (IJ25) 6,247,796 (Jul. 10, 1998 PO8004 15-Jul-97 ImageCreation Method and Apparatus (IJ26) 09/113,122 (Jul. 10, 1998 PO803715-Jul-97 Image Creation Method and Apparatus (IJ27) 6,390,603 (Jul. 10,1998 PO8043 15-Jul-97 Image Creation Method and Apparatus (IJ28)6,362,843 (Jul. 10, 1998 PO8042 15-Jul-97 Image Creation Method andApparatus (IJ29) 6,293,653 (Jul. 10, 1998 PO8064 15-Jul-97 ImageCreation Method and Apparatus (IJ30) 6,312,107 (Jul. 10, 1998 PO938923-Sep-97 Image Creation Method and Apparatus (IJ31) 6,227,653 (Jul. 10,1998 PO9391 23-Sep-97 Image Creation Method and Apparatus (IJ32)6,234,609 (Jul. 10, 1998 PP0888 12-Dec-97 Image Creation Method andApparatus (IJ33) 6,238,040 (Jul. 10, 1998 PP0891 12-Dec-97 ImageCreation Method and Apparatus (IJ34) 6,188,415 (Jul. 10, 1998 PP089012-Dec-97 Image Creation Method and Apparatus (IJ35) 6,227,654 (Jul. 10,1998 PP0873 12-Dec-97 Image Creation Method and Apparatus (IJ36)6,209,989 (Jul. 10, 1998 PP0993 12-Dec-97 Image Creation Method andApparatus (IJ37) 6,247,791 (Jul. 10, 1998 PP0890 12-Dec-97 ImageCreation Method and Apparatus (IJ38) 6,336,710 (Jul 10, 1998 PP139819-Jan-98 An Image Creation Method and Apparatus 6,217,153 (IJ39) (Jul.10, 1998 PP2592 25-Mar-98 An Image Creation Method and Apparatus6,416,167 (IJ40) (Jul. 10, 1998 PP2593 25-Mar-98 Image Creation Methodand Apparatus (IJ41) 6,243,113 (Jul. 10, 1998 PP3991  9-Jun-98 ImageCreation Method and Apparatus (IJ42) 6,283,581 (Jul. 10, 1998 PP3987 9-Jun-98 Image Creation Method and Apparatus (IJ43) 6,247,790 (Jul. 10,1998 PP3985  9-Jun-98 Image Creation Method and Apparatus (IJ44)6,260,953 (Jul. 10, 1998 PP3983  9-Jun-98 Image Creation Method andApparatus (IJ45) 6,267,469 (Jul. 10, 1998Ink Jet Manufacturing

Further, the present application may utilize advanced semiconductorfabrication techniques in the construction of large arrays of ink jetprinters. Suitable manufacturing techniques are described in thefollowing Australian provisional patent specifications incorporated hereby cross-reference. The serial numbers of respective corresponding USpatent applications are also provided for the sake of convenience.

Australian U.S. Pat. No./ Provisional Patent Application Number FilingDate Title and Filing Date PO7935 15-Jul-97 A Method of Manufacture ofan Image Creation 6,224,780 Apparatus (IJM01) (Jul. 10, 1998) PO793615-Jul-97 A Method of Manufacture of an Image Creation 6,235,212Apparatus (IJM02) (July 10, 1998) PO7937 15-Jul-97 A Method ofManufacture of an Image Creation 6,280,643 Apparatus (IJM03) (Jul. 10,1998) PO8061 15-Jul-97 A Method of Manufacture of an Image Creation6,284,147 Apparatus (IJM04) (Jul. 10, 1998) PO8054 15-Jul-97 A Method ofManufacture of an Image Creation 6,214,244 Apparatus (IJM05) (Jul. 10,1998) PO8065 15-Jul-97 A Method of Manufacture of an Image Creation6,071,750 Apparatus (IJM06) (Jul. 10, 19980 PO8055 15-Jul-97 A Method ofManufacture of an Image Creation 6,267,905 Apparatus (IJM07) (Jul. 10,1998) PO8053 15-Jul-97 A Method of Manufacture of an Image Creation6,251,298 Apparatus (IJM08) (Jul. 10, 1998) PO8078 15-Jul-97 A Method ofManufacture of an Image Creation 6,258,285 Apparatus (IJM09) (Jul. 10,1998) PO7933 15-Jul-97 A Method of Manufacture of an Image Creation6,225,138 Apparatus (IJM10) (Jul. 10, 1998) PO7950 15-Jul-97 A Method ofManufacture of an Image Creation 6,241,904 Apparatus (IJM11) (Jul. 10,1998) PO7949 15-Jul-97 A Method of Manufacture of an Image Creation6,299,786 Apparatus (IJM12) (Jul. 10, 1998) PO8060 15-Jul-97 A Method ofManufacture of an Image Creation 09/113,124 Apparatus (IJM13) (Jul. 10,1998) PO8059 15-Jul-97 A Method of Manufacture of an Image Creation6,231,773 Apparatus (IJM14) (Jul. 10, 1998) PO8073 15-Jul-97 A Method ofManufacture of an Image Creation 6,190,931 Apparatus (IJM15) (Jul. 10,1998) PO8076 15-Jul-97 A Method of Manufacture of an Image Creation6,248,249 Apparatus (IJM16) (Jul. 10, 1998) PO8075 15-Jul-97 A Method ofManufacture of an Image Creation 6,290,862 Apparatus (IJM17) (Jul. 10,1998) PO8079 15-Jul-97 A Method of Manufacture of an Image Creation6,241,906 Apparatus (IJM18) (Jul. 10, 1998) PO8050 15-Jul-97 A Method ofManufacture of an Image Creation 09/113,116 Apparatus (IJM19) (Jul. 10,1998) PO8052 15-Jul-97 A Method of Manufacture of an Image Creation6,241,905 Apparatus (IJM20) (Jul. 10, 1998) PO7948 15-Jul-97 A Method ofManufacture of an Image Creation 6,451,216 Apparatus (IJM21) (Jul. 10,1998) PO7951 15-Jul-97 A Method of Manufacture of an Image Creation6,231,772 Apparatus (IJM22) (Jul. 10, 1998) PO8074 15-Jul-97 A Method ofManufacture of an Image Creation 6,274,056 Apparatus (IJM23) (Jul. 10,1998) PO7941 15-Jul-97 A Method of Manufacture of an Image Creation6,290,861 Apparatus (IJM24) (Jul. 10, 1998) PO8077 15-Jul-97 A Method ofManufacture of an Image Creation 6,248,248 Apparatus (IJM25) (Jul. 10,1998) PO8058 15-Jul-97 A Method of Manufacture of an Image Creation6,306,671 Apparatus (IJM26) (Jul. 10, 1998) PO8051 15-Jul-97 A Method ofManufacture of an Image Creation 6,331,258 Apparatus (IJM27) (Jul. 10,1998) PO8045 15-Jul-97 A Method of Manufacture of an Image Creation6,110,754 Apparatus (IJM28) (Jul. 10, 1998) PO7952 15-Jul-97 A Method ofManufacture of an Image Creation 6,294,101 Apparatus (IJM29) (Jul. 10,1998) PO8046 15-Jul-97 A Method of Manufacture of an Image Creation6,416,679 Apparatus (IJM30) (Jul. 10, 1998) PO8503 11-Aug-97 A Method ofManufacture of an Image Creation 6,264,849 Apparatus (IJM30a) (Jul. 10,1998) PO9390 23-Sep-97 A Method of Manufacture of an Image Creation6,254,793 Apparatus (IJM31) (Jul. 10, 1998) PO9392 23-Sep-97 A Method ofManufacture of an Image Creation 6,235,211 Apparatus (IJM32) (Jul. 10,1998) PP0889 12-Dec-97 A Method of Manufacture of an Image Creation6,235,211 Apparatus (IJM35) (Jul. 10, 1998) PP0887 12-Dec-97 A Method ofManufacture of an Image Creation 6,264,850 Apparatus (IJM36) (Jul. 10,1998) PP0882 12-Dec-97 A Method of Manufacture of an Image Creation6,258,284 Apparatus (IJM37) (Jul. 10, 1998) PP0874 12-Dec-97 A Method ofManufacture of an Image Creation 6,258,284 Apparatus (IJM38) (Jul. 10,1998) PP1396 19-Jan-98 A Method of Manufacture of an Image Creation6,228,668 Apparatus (IJM39) (Jul. 10, 1998) PP2591 25-Mar-98 A Method ofManufacture of an Image Creation 6,180,427 Apparatus (IJM41) (Jul. 10,1998) PP3989  9-Jun-98 A Method of Manufacture of an Image Creation6,171,875 Apparatus (IJM40) (Jul. 10, 1998) PP3990  9-Jun-98 A Method ofManufacture of an Image Creation 6,267,904 Apparatus (IJM42) (Jul. 10,1998) PP3986  9-Jun-98 A Method of Manufacture of an Image Creation6,245,247 Apparatus (IJM43) (Jul. 10, 1998) PP3984  9-Jun-98 A Method ofManufacture of an Image Creation 6,245,247 Apparatus (IJM44) (Jul. 10,1998) PP3982  9-Jun-98 A Method of Manufacture of an Image Creation6,231,148 Apparatus (IJM45) (Jul. 10, 1998)Fluid Supply

Further the present application may utilize an ink delivery system tothe ink jet head. Delivery systems relating to the supply of ink to aseries of ink jet nozzles are described in the following Australianprovisional patent specifications, the disclosure of which are herebyincorporated by cross-reference. The serial numbers of respectivecorresponding US patent applications are also provided for the sake ofconvenience.

U.S. Pat. No./ Australian Patent Provisional Application Number FilingDate Title and Filing Date PO8003 15-Jul-97 Supply method 6,350,023 andApparatus (F1) (Jul. 10, 1998) PO8005 15-Jul-97 Supply method 6,318,849and Apparatus (F2) (Jul. 10, 1998)MEMS Technology

Further, the present application may utilize advanced semiconductormicroelectromechanical techniques in the construction of large arrays ofink jet printers. Suitable microelectromechanical techniques aredescribed in the following Australian provisional patent specificationsincorporated here by cross-reference. The serial numbers of respectivecorresponding US patent applications are also provided for the sake ofconvenience.

U.S. Pat. No./ Australian Patent Provisional Application Number FilingDate Title and Filing Date PO8006 15-Jul-97 A device (MEMS02) 6,087,638(Jul. 10, 1998) PO8007 15-Jul-97 A device (MEMS03) 09/113,093 (July 10,1998) PO8008 15-Jul-97 A device (MEMS04) 6,340,222 (Jul. 10, 1998)PO8010 15-Jul-97 A device (MEMS05) 6,041,600 (Jul. 10, 1998) PO801115-Jul-97 A device (MEMS06) 6,299,300 (Jul. 10, 1998) PO7947 15-Jul-97 Adevice (MEMS07) 6,067,797 (Jul. 10, 1998) PO7944 15-Jul-97 A device(MEMS09) 6,286,935 (Jul. 10, 1998) PO7946 15-Jul-97 A device (MEMS10)6,044,646 (Jul. 10, 1998) PO9393 23-Sep-97 A Device and Method09/113,065 (MEMS11) (Jul. 10, 1998) PP0875 12-Dec-97 A Device (MEMS12)09/113,078 (Jul. 10, 1998) PP0894 12-Dec-97 A Device and Method6,382,769 (MEMS13) (Jul. 10, 1998)IR Technologies

Further, the present application may include the utilization of adisposable camera system such as those described in the followingAustralian provisional patent specifications incorporated here bycross-reference. The serial numbers of respective corresponding USpatent applications are also provided for the sake of convenience.

U.S. Pat. No./ Australian Patent Provisional Application Number FilingDate Title and Filing Date PP0895 12-Dec-97 An Image Creation 6,231,148Method and (Jul. 10, 1998) Apparatus (IR01) PP0870 12-Dec-97 A Deviceand Method 09/113,106 (IR02) (Jul. 10, 1998) PP0869 12-Dec-97 A Deviceand Method 6,293,658 (IR04) (Jul. 10, 1998) PP0887 12-Dec-97 ImageCreation 6,614,560 Method and (Jul. 10, 1998) Apparatus (IR05) PP088512-Dec-97 An Image Production 6,238,033 System (IR06) (Jul. 10, 1998)PP0884 12-Dec-97 Image Creation 6,312,070 Method and (Jul. 10, 1998)Apparatus (IR10) PP0886 12-Dec-97 Image Creation 6,238,111 Method and(Jul. 10, 1998) Apparatus (IR12) PP0871 12-Dec-97 A Device and09/113,086 Method (IR13) (Jul. 10, 1998) PP0876 12-Dec-97 An ImageProcessing 09/113,094 Method and (Jul. 10, 1998) Apparatus (IR14) PP087712-Dec-97 A Device and 6,378,970 Method (IR16) (Jul. 10, 1998 PP087812-Dec-97 A Device and 6,196,739 Method (IR17) (Jul. 10, 1998) PP088312-Dec-97 A Device and 6,270,182 Method (IR19) (Jul. 10, 1998) PP088012-Dec-97 A Device and 6,152,619 Method (IR20) (Jul. 10, 1998) PP088112-Dec-97 A Device and 09/113,092 Method (IR21) (Jul. 10, 1998)DotCard Technologies

Further, the present application may include the utilization of a datadistribution system such as that described in the following Australianprovisional patent specifications incorporated here by cross-reference.The serial numbers of respective corresponding US patent applicationsare also provided for the sake of convenience.

U.S. Pat. No./ Australian Patent Provisional Application Number FilingDate Title and Filing Date PP2370 16-Mar-98 Data Processing Method6,786,420 and Apparatus (Dot01) (Jul. 10, 1998) PP2371 16-Mar-98 DataProcessing Method 09/113,052 and Apparatus (Dot02) (Jul. 10, 1998)Artcam Technologies

Further, the present application may include the utilization of cameraand data processing techniques such as an Artcam type device asdescribed in the following Australian provisional patent specificationsincorporated here by cross-reference. The serial numbers of respectivecorresponding US patent applications are also provided for the sake ofconvenience.

U.S. Pat. No./ Australian Patent Provisional Application Number FilingDate Title and Filing Date PO7991 15-Jul-97 Image Processing Method andApparatus 6,750,901 (ART01) (Jul. 10, 1998) PO7988 15-Jul-97 ImageProcessing Method and Apparatus 6,476,863 (ART02) (Jul. 10, 1998) PO799315-Jul-97 Image Processing Method and Apparatus 6,788,336 (ART03) (Jul.10, 1998) PO9395 23-Sep-97 Data Processing Method and Apparatus6,322,181 (ART04) (Jul. 10, 1998) PO8017 15-Jul-97 Image ProcessingMethod and Apparatus 6,597,817 (ART06) (Jul. 10, 1998) PO8014 15-Jul-97Media Device (ART07) 6,227,648 (Jul. 10, 1998) PO8025 15-Jul-97 ImageProcessing Method and Apparatus 6,727,948 (ART08) (Jul. 10, 1998) PO803215-Jul-97 Image Processing Method and Apparatus 6,690,419 (ART09) (Jul.10, 1998) PO7999 15-Jul-97 Image Processing Method and Apparatus6,727,951 (ART10) (Jul. 10, 1998) PO7998 15-Jul-97 Image ProcessingMethod and Apparatus 09/112,742 (ART11) (Jul. 10, 1998) PO8031 15-Jul-97Image Processing Method and Apparatus 09/112,741 (ART12) (Jul. 10, 1998)PO8030 15-Jul-97 Media Device (ART13) 6,196,541 (Jul. 10, 1998) PO799715-Jul-97 Media Device (ART15) 6,195,150 (Jul. 10, 1998) PO797915-Jul-97 Media Device (ART16) 6,362,868 (Jul. 10, 1998) PO801515-Jul-97 Media Device (ART17) 09/112,738 (Jul. 10, 1998) PO797815-Jul-97 Media Device (ART18) 09/113,067 (Jul. 10, 1998) PO798215-Jul-97 Data Processing Method and Apparatus 6,431,669 (ART19) (Jul.10, 1998 PO7989 15-Jul-97 Data Processing Method and Apparatus 6,362,869(ART20) (Jul. 10, 1998 PO8019 15-Jul-97 Media Processing Method andApparatus 6,472,052 (ART21) (Jul. 10, 1998 PO7980 15-Jul-97 ImageProcessing Method and Apparatus 6,356,715 (ART22) (Jul. 10, 1998) PO801815-Jul-97 Image Processing Method and Apparatus 09/112,777 (ART24) (Jul.10, 1998) PO7938 15-Jul-97 Image Processing Method and Apparatus6,636,216 (ART25) (Jul. 10, 1998) PO8016 15-Jul-97 Image ProcessingMethod and Apparatus 6,366,693 (ART26) (Jul. 10, 1998) PO8024 15-Jul-97Image Processing Method and Apparatus 6,329,990 (ART27) (Jul. 10, 1998)PO7940 15-Jul-97 Data Processing Method and Apparatus 09/113,072 (ART28)(Jul. 10, 1998) PO7939 15-Jul-97 Data Processing Method and Apparatus6,459,495 (ART29) (Jul. 10, 1998) PO8501 11-Aug-97 Image ProcessingMethod and Apparatus 6,137,500 (ART30) (Jul. 10, 1998) PO8500 11-Aug-97Image Processing Method and Apparatus 6,690,416 (ART31) (Jul. 10, 1998)PO7987 15-Jul-97 Data Processing Method and Apparatus 09/113,071 (ART32)(Jul. 10, 1998) PO8022 15-Jul-97 Image Processing Method and Apparatus6,398,328 (ART33) (Jul. 10, 1998 PO8497 11-Aug-97 Image ProcessingMethod and Apparatus 09/113,090 (ART34) (Jul. 10, 1998) PO8020 15-Jul-97Data Processing Method and Apparatus 6,431,704 (ART38) (Jul. 10, 1998PO8023 15-Jul-97 Data Processing Method and Apparatus 09/113,222 (ART39)(Jul. 10, 1998) PO8504 11-Aug-97 Image Processing Method and Apparatus09/112,786 (ART42) (Jul. 10, 1998) PO8000 15-Jul-97 Data ProcessingMethod and Apparatus 6,415,054 (ART43) (Jul. 10, 1998) PO7977 15-Jul-97Data Processing Method and Apparatus 09/112,782 (ART44) (Jul. 10, 1998)PO7934 15-Jul-97 Data Processing Method and Apparatus 6,665,454 (ART45)(Jul. 10, 1998) PO7990 15-Jul-97 Data Processing Method and Apparatus6,542,645 (ART46) (Jul. 10, 1998) PO8499 11-Aug-97 Image ProcessingMethod and Apparatus 6,486,886 (ART47) (Jul. 10, 1998) PO8502 11-Aug-97Image Processing Method and Apparatus 6,381,361 (ART48) (Jul. 10, 1998)PO7981 15-Jul-97 Data Processing Method and Apparatus 6,317,192 (ART50)(Jul. 10, 1998 PO7986 15-Jul-97 Data Processing Method and Apparatus09/113,057 (ART51) (Jul. 10, 1998) PO7983 15-Jul-97 Data ProcessingMethod and Apparatus 6,646,757 (ART52) (Jul. 10, 1998) PO8026 15-Jul-97Image Processing Method and Apparatus 09/112,752 (ART53) (Jul. 10, 1998)PO8027 15-Jul-97 Image Processing Method and Apparatus 09/112,759(ART54) (Jul. 10, 1998) PO8028 15-Jul-97 Image Processing Method andApparatus 6,624,848 (ART56) (Jul. 10, 1998) PO9394 23-Sep-97 ImageProcessing Method and Apparatus 6,357,135 (ART57) (Jul. 10, 1998 PO939623-Sep-97 Data Processing Method and Apparatus 09/113,107 (ART58) (Jul.10, 1998) PO9397 23-Sep-97 Data Processing Method and Apparatus6,271,931 (ART59) (Jul. 10, 1998) PO9398 23-Sep-97 Data ProcessingMethod and Apparatus 6,353,772 (ART60) (Jul. 10, 1998) PO9399 23-Sep-97Data Processing Method and Apparatus 6,106,147 (ART61) (Jul. 10, 1998)PO9400 23-Sep-97 Data Processing Method and Apparatus 6,665,008 (ART62)(Jul. 10, 1998) PO9401 23-Sep-97 Data Processing Method and Apparatus6,304,291 (ART63) (Jul. 10, 1998) PO9402 23-Sep-97 Data ProcessingMethod and Apparatus 09/112,788 (ART64) (Jul. 10, 1998) PO9403 23-Sep-97Data Processing Method and Apparatus 6,305,770 (ART65) (Jul. 10, 1998)PO9405 23-Sep-97 Data Processing Method and Apparatus 6,289,262 (ART66)(Jul. 10, 1998) PP0959 16-Dec-97 A Data Processing Method and Apparatus6,315,200 (ART68) (Jul. 10, 1998) PP1397 19-Jan-98 A Media Device(ART69) 6,217,165 (Jul. 10, 1998)

1. A digital camera, comprising: an image capture assembly; a housingadapted to locate a roll of print media; a print media transportassembly to transport the print media along a path; a pagewidthmicroelectromechanical ink jet printhead operable to print across thepath; an internal chassis serving as a frame on which the image captureassembly, the print media transport assembly, and the printhead aredirectly supported; and an external casing completely encasingtherewithin the internal chassis, wherein the external casing isopenable, and the internal chassis together with the assemblies andprinthead supported thereon are removable from the external casing.
 2. Adigital camera according to claim 1, comprising: a print media severingassembly provided at an exit of the path.
 3. A digital camera accordingto claim 2, wherein the print media severing assembly comprises a blademounted upon a worm screw disposed along the exit.
 4. A digital cameraaccording to claim 3, wherein the wormscrew is driven by a motorcontrolled by the processing integrated circuit.
 5. A digital cameraaccording to claim 3, wherein the print media severing assembly isarranged to increment a counter each time the print media severingassembly operates.
 6. A digital camera according to claim 1, furthercomprising a recapping mechanism adapted to cap the printhead betweenprinting operations.
 7. digital camera according to claim 6, wherein therecapping mechanism includes a biasing member arranged to bias a cappingportion of the recapping mechanism to a capping position and a solenoidcoil arranged to overcome the biasing member during printing operations.8. A digital camera according to claim 7, further comprising aprocessing integrated circuit in communication with the image captureassembly.
 9. A digital camera according to claim 8, wherein the solenoidcoil is controlled by the processing integrated circuit.